Fossil and Recent 

Calcareous Algae 

From Guam

GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G
Fossil and Recent 

Calcareous Alo:ae 

From Guam

By J. HARLAN JOHNSON

GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G

Of the 82 species-groups listed or described, 

2O are new; discussion includes stratigraphic 

distribution and correlation with Saipan floras

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1964
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEW ART L. UDALL, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office

Washington, D.C. 20402
CONTENTS

Abstract.__________________________________________

Introduction _______________________________________

Acknowledgments_ _ _ __--_---____-_-_______________

Classification of calcareous algae._____________________

Stratigraphic distribution of Guam algae_____________

Eocene and Oligocene, Tertiary &_________________

Lower Miocene, Tertiary e_______________________

Lower Miocene, Tertiary/_______________________

Upper Miocene and Pliocene, Tertiary g_ __________

Pliocene and Pleistocene.__-_--__--_-___-______-_

Correlation ________________________________________

Localities __________________________________________

Systematic descriptions._____________________________

Phyllum Rhodophyta (red algae)_________________

Family Corallinaceae (coralline algae)_________

Subfamily Melobesioideae (crustose coralline algae) ________________________ __. _

Genus Archaeolithothamnium Rothpletz, 

1891____________________________

Genus Lithothamnium Philippi, 1837-__ 

Genus Mesophyllum Lemoine, 1928____

Genus Lithophyllum Philippi, 1837____

Genus Porolithon Foslie, 1909________

Gl 

1 

1 

1

1

2

3

4

4

4

5

6

9

9

9

9

9

10

14

16

23

Systematic descriptions Continued 

Phyllum Rhodophyta Continued

Family Corallinaceae Continued

Subfamily Melobesioideae Continued

Genus Goniolithon Foslie, 1900______

Genus Aethesolithon Johnson, n. gen___ 

Genus Lithoporella Foslie, 1909_______

Genus Dermatolithon Foslie, 1899_____

Genus Melobesia Lamouroux, 1812____

Subfamily Corallinoideae (articulate coralline algae) ___________________________

Genus Calliarthron Manza, 1937------

Genus Amphiroa Lamouroux, 1812____

Genus Corallina Linnaeus, 1758_______

Genus Arthrocardia Decaisne, 1842, 

emend. Areschoug, 1850_ __________

Genus Jania Lamouroux, 1812_______

Chlorophyta (green algae)______________---_--__-

Family Dasycladaceae______________---____--

Genus Cymopolia Lamouroux, 1816___ 

Family Codiaceae________________----__-----

Genus Halimeda Lamouroux _________

References cited._______________________---_-___----

Index ____________-______--_---_-___--_-_---_------

G24

27

28

29

30

30

31

31

34

36

36

36

36

36

37

37

37

39

ILLUSTRATIONS

[Plates follow Index]

PLATE 1. Miocene Lithothamnium.

2. Miocene Lithothamnium and Mesophyllum.

3. Miocene Mesophyllum and Lithophyllum. 

4-7. Miocene Lithophyllum.

8. Miocene Goniolithon.

9. Miocene Aethesolithon n. gen.

10. Miocene Dermatolithon, Lithoporella, Melobesia, 

Archaeolithothamnium, and Aethesolithon; and 

Pliocene and Pleistocene Dermatolithon.

PLATE 11. Miocene Amphiroa and Corallina.

12. Eocene Cymopolia; Miocene Jania, Halimeda, 

Corallina, and Lithophyllum; Pliocene and Pleistocene Halimeda; and Pleistocene Amphiroa.

13. Recent Lithophyllum and Goniolithon.

14. Recent Lithophyllum.

15. Recent Goniolithon and Lithophyllum.

Page 

FIGURE 1. Map of Guam showing sample-collecting

localities of calcareous algae ___________ G7

TABLES

TABLE 1. Genera of calcareous algae found in the 

Cenozoic deposits of Guam ___________

2-4. Stratigraphic distribution of 

2. Fossil algae of Guam ______________

3. Eocene algae on Guam and Saipan-_

4. Miocene algae on Guam and Saipan. _

5. Algae of the Mariana Limestone on Guam 

and Saipan _________________________

6. Field and permanent catalog numbers for 

fossil algae from Guam_______________

Page 

G2

2

5

5

TABLES 7-10. Measurements, in microns, and distribution of species of 

7. Archaeolithothamnium from Guam___

8. Lithothamnium from Guam_________

9. Lithophyllum from Guam_ _________

10. Goniolithon from Guam.___________

11. Detailed measurements, in microns, 

of species of Aethesolithon from 

Guam_ ___________-___-----_

Page

G10 

11 

16 

24

27

GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM

By J. HAELAN JOHNSON

ABSTRACT

Eighty-two species of calcareous algae belonging to 16 genera 

are described and 68 are named specifically. Of these, 1 genus 

Aethesolithon, and 20 species are described as new.

Remains of calcareous algae occur in all the Cenozoic limestones of Guam. Locally the algae are sufficiently abundant to 

be considered as rock builders. Each formation has a distinctive 

flora. The algal floras are similar to those found in beds of similar 

age on Saipan.

The evidence indicates that fossil algae are useful as environmental indicators and also for dating the strata.

INTRODUCTION

The term "calcareous algae" has been applied to 

those algae that have developed the ability to secrete or 

deposit calcium carbonate within or around their tissues. 

Remains of such algae have been found in appreciable 

numbers in most of the limestones of Cenozoic age that 

have been studied on Guam. At some localities, algae 

occur in sufficient abundance to be important contributors to the building of the limestones.

The geological work on Guam furnished an opportunity to study a large series of specimens of algae from 

rocks that have been dated by means of Foraminifera, 

which increases our knowledge of the stratigraphic 

distribution of these fossils.

This study is based on a collection of large thin sections of limestone obtained from localities on Guam, 

representing material collected by the various members 

of the Guam field party from June 1952 to October 1954, 

as part of the Pacific Geological Mapping Program of 

the U.S. Geological Survey and Corps of Engineers 

of the U.S. Army. Additional material was obtained 

by the author on visits made to the island in 1949, 1951, 

and 1952. The thin sections have an average area of 

3 square inches and show many unoriented sections of 

fragments of fossil algae. Selected specimens exhibiting the structure necessary for identification were photographed and studied.

Species illustrated in the recent U.S. Geological 

Survey Professional Papers on Bikini CProf. Paper 260) 

and Saipan (Prof. Paper 280) are not illustrated in this 

report unless they show additional features.

ACKNOWLEDGMENTS

Mr. A. P. Bronson, manager of "Shells of Micronesia," the aquarium and curio store on Guam, greatly 

assisted the author in excursions to the modern reef and 

helped him obtain many excellent specimens. H. S. 

Ladd made valuable suggestions on the arrangement 

and preparation of the manuscript. The Colorado 

School of Mines supplied the laboratory and photographic studies for the work.

CLASSIFICATION OF CALCAREOUS ALGAE'

Recent algae are classified into several broad groups 

on the basis of the structure and physiology of the 

plants and the basic chemical ingredients of their 

normal pigments. Only four of these contain members that have developed the ability to secrete or deposit 

calcium carbonate. These are the Rhodophyta or red 

algae, the Phaeophyta or brown algae, the Chlorophyta 

or green algae, and the Cyanophyta or blue-green 

algae. The Rhodophyta and Chlorophyta include 

most of the lime-secreting and lime-depositing algae 

which form readily identifiable fossils. They include 

all the forms discussed from Guam. Table 1 shows the 

classification used in this report. A previous report 

discusses terminology, structure, and a key for identification of fossil algae (Johnson, 1957, p. 210, 216).

STRATIGRAPHIC DISTRIBUTION OF GUAM ALGAE

The characteristic features of each formation are 

summarized in the following paragraphs followed by a 

list showing the algal flora of each. Table 2 shows the 

stratigraphic distribution of the various species.

Gl
G2 GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

TABLE 1. Genera of calcareous algae found in the Cenozoic 

deposits of Guam

Phylum

Rhodophyta (red

algae).

Chlorophyta 

(green algae) .

Family

Corallinaceae __

Dasycladaceae

Codlaceae

Subfamily

Melobesioideae

(crustose corallines).

Corallinoideae

(articulate corallines) .

Genera

Archaeolithothamnium

Lithothamnium

Mesophyllum

Lithophyllum

Porolithon

Otmiolithon

Aethesolithon

n. gen.

Lithoporella

Dermatolithon

Melobesia

Calliarthron

Amphiroa

Corallina

Arthrocardia

Jania

Cymopolia 

Halimeda

EOCENE AND OLIGOCENE, TERTIARY b

Alutom Formation. This formation is a series of 

volcanic lava flows, reworked tuffaceous sandstone and 

shale, and volcanic breccia. Scarce limestone beds in 

the formation and abundant limestone pebbles and

fragments in the breccia contain calcareous algae and 

Foraminifera. Although a part of the formation contains Foraminifera 01 Tertiary c age, the limestone 

fragments contained a fauna of Tertiary b age only 

(Cole, 1963).

Algal flora of the Alutom Formation

Archaeolithothamnium saipanense Johnson 

Lithothamnium cf. L. aggregatum Lemoine

crispithallus Johnson

marianae Johnson

tagpotchaenses Johnson

sp. A Johnson 

Lithophyllum sp. A Johnson 

Lithoporella melobesioides Foslie 

Dermatolithon niiida Johnson 

Arihrocardial sp. 

Corallina matansa Johnson

prisca Johnson 

Janial sp.

Cymopolia cf. C. pacifica Johnson 

Perforating algae 

Halimedal sp.

TABLE 2. Stratigraphic distribution of the fossil algae of Guam

Formation or member

Species

cf. L. saipanense Johnson - -_- - -

sp. G - -----------__---------_---____-.-.--

sp. A.- . _ _ ......... __ __.,.. __ ...

cf. L. araii Ishijima. . . ... ______

sp. H...______. --- _ -_-_ _____________-- __________

mart anae Johnson. . _ ------- ..... .. _ ._. _ . .....

sp F

Mesophyllum commune Lemoine _ _ .. -.-.-...- . . 

grande Johnson n. sp _ . ------- ... 

guamense Johnson n. sp - . - ----- - _ _ -

savornini Lemoine.. ------ - _.__ ------------ 

sp. C. ----__.-__---_.----.._______-._-_.--____ 

sp. D ... --.__---_----._..-.___ -_.-...-.-----------_ -_--

Eocene and 

Oligocene

Alutom 

Formation

X 

X

X

X 

X

X

Miocene

Maemong 

Limestone 

Member of 

Umatac 

Formation

X

X

X

X

X

X

X 

X

X

X 

X 

X

X

Bonya 

Limestone

X

X

Miocene and Pliocene

Alifan 

Limestone

X 

X

X

X

X

X

Barrigada 

Limestone

Pliocene and 

Pleistocene

Mariana 

Limestone

X

Recent

Recent reefs
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM

TABLE 2. Stratigraphic distribution of the fossil algae of Guam Continued

Species

sp. B_. ______________________________________________________ __ ..

sp. 0..... ..................... .............. .....................

sp. B............................ .................................

prefragtJissima Lemoine _________________________

cf. A. regularis Johnson and Ferris ____ __ . _

sp.C. ............................................................

sp. D _ . _ . _____ ___________ . _ ....

neuschelorum Johnson... ____ ___

Cymopolia cf. C. padfica Johnson _________________

Halimeda ............ ................ .

Formation or member

Eocene and 

Oligocene

Alutom 

Formation

X

X

X

X

X

X

X

X

Miocene

Maemong 

Limestone 

Member of 

Umatac 

Formation

X

X

X

X 

X

X 

X

X 

X

X

X 

X

X 

X

X

X

X

X

X 

X

X

Bonya 

Limestone

X

X

X

X

X

X

X

X

X

X

X

Miocene and Pliocene

Alifan 

Limestone

X

X

X

X 

X

X

X 

X

X

X 

X

X

X

Barrigada 

Limestone

X

X

X

X

X

Pliocene and 

Pleistocene

Mariana 

Limestone

X

X

X

X

X

X

Eecent

Recent reefs

X

X

X 

X

X 

X 

X

X

X

LOWER MIOCENE, TERTIARY e

Maemong Limestone Member of the Umatac Formation. Limestone tongues in the Facpi Volcanic Member 

of this formation contain abundant calcareous algae 

and Foraminifera that have been dated by Cole (1963) 

as Tertiary e. Pebbles, fragments, and angular blocks

of the limestone incorporated in the overlying Bolanos 

Pyroclastic Member of the Umatac Formation contain 

the same fauna and flora and in this report will all be 

referred to as Maemong Limestone Member. This 

limestone contains the richest algal flora of any of the 

Guam limestones, with a total of 36 species.
GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

Algal flora of the Maemong Limestone Member

Archaeolithothamnium lauense Johnson and Ferris

taiwanensis Ishijima 

Lithothamnium cf. L. araii Ishijima

bourcarti Lemoine

ef. L. crispatum Hauek

maemongense Johnson, n. sp.

ef. L. peleense Lemoine

sp. F

sp. G

sp. 

Mesophyllum commune Lemoine

grande Johnson, n. sp.

guamense Johnson, n. sp.

pacificum Johnson

sp. D 

Lithophyllum ef. L. kladosum Johnson

maemongense Johnson, n. sp.

ef. L. obliquum Lemoine

schlangeri Johnson, n. sp.

traceyi Johnson, n. sp.

prelichenoides Lemoine

pseudoamphiroa Johnson, n. sp.

sp. B

sp. C

sp.

Goniolithon miocenicum Johnson, n. sp. 

Lithoporella melobesioides Foslie

sp. A 

Dermatolithon guamensis Johnson, n. sp.

sp. A

Melobesia guamensis Johnson, n. sp. 

Calliarthron antiquum Johnson 

Corallina neuschelorum Johnson 

Arthrocardia? sp. 

Jania guamensis Johnson, n. sp.

vetus Johnson 

Halimeda? sp.

LOWER MIOCENE, TERTIARY /

Bony a Limestone. This detrital limestone contains a 

foraminiferal fauna closely similar to that in the Futuna 

Limestone of Fiji, according to Cole (1963). Calcareous algae are reasonably abundant, but the flora is 

rather restricted in variety.

Algal flora of the Bonya Limestone

Lithothamnium bonyense Johnson, n. sp.

Mesophyllum sp. C

Lithophyllum alternicellum Johnson, n. sp.

bonyense Johnson, n. sp.

cf. L. prelichenoides Lemoine

quadrangulum var. welschi Lemoine 

Aethesolithon problematicum Johnson, n. sp. 

Lithoporella melobesioides Foslie 

Amphiroa anchiverricosa Johnson and Ferris

tan-i Ishijima 

Amphiroa? sp.

Jania guamensis Johnson, n. sp. 

Halimeda? sp.

UPPER MIOCENE AND PLIOCENE, TERTIARY g

Alifan Limestone. The lower part of this formation 

is a pink detrital limestone that contains a species of

larger Foraminifera, Rotalia aijehensis, that is found 

throughout the Bonya Limestone (Cole, 1963), the 

lower part of which contains a good Tertiary / fauna. 

The lower part of the Alifan therefore may be as old 

as Tertiary / but probably is Tertiary g in age. No 

calcareous algae are described from the upper part of 

the formation.

Algal flora of the Alifan Limestone

Archaeolithothamnium cf. A. puntiense Airoldi

taiwanensis Ishijima 

Lithothamnium alifanense Jonhson, n. sp.

saipanense Johnson

sp. H

Mesophyllum savornini Lemoine 

Lithophyllum alifanense Johnson, n. sp.

alternatum Johnson, n. sp.

cf. L. glangeaudi Lemoine

sp. F

sp. G

Goniolithon sp. C

Aethesolithon grandis Johnson, n. sp. 

Lithoporella melobesioides Foslie 

Dermatolithon sp. B 

Amphiroa prefragilissima Lemoine

cf. A. regularis Johnson and Ferris 

Corallina sp. A 

Perforating algae 

Halimedaf sp.

Barrigada Limestone. This white detrital bank-type 

limestone contains a larger foraminiferal assemblage 

which is thought by Cole (1963) to indicate deposition 

in banks probably during Tertiary g time. Field relations suggest that the Barrigada Limestone is contemporaneous with a part of the Alifan Limestone. 

Macerated fragments of calcareous algae, too small 

and worn to permit specific determination, are fairly 

numerous, but few species could be identified.

Algal flora of the Barrigada Limestone

Lithophyllum sp. E 

Lithoporella melobesioides Foslie 

Amphiroa ef. A. verricosa Ktitzing

sp. D 

Halimeda? sp.

PLIOCENE AND PLEISTOCENE

Mariana Limestone. This limestone forms most of 

the reeflike deposits of the north plateau of the island. 

A reef facies, a detrital (lagoonal) facies, a molluscan 

(lagoonal) facies, and a fore-reef facies were mapped, 

but in the samples studied, calcareous algae were found 

only from the reef and fore-reef facies. The Mariana 

Limestone probably formed during both Pliocene and 

Pleistocene time; according to Cole (1963), larger 

Foraminifera from the fore-reef facies of the Mariana 

Limestone are of Pleistocene age. All the determinable 

algae are of Recent species, practically all of which can 

be found growing on the Recent reefs around the island.
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM

The selected samples of the Mariana Limestone from 

Guam do not contain algae as abundantly as the similar 

deposits on Saipan (Johnson, 1957), and the number of 

forms identified is smaller. All the species identified 

from the limestone of Guam also occurred on Saipan, 

but Saipan had many additional species.

Algal flora of the Mariana Limestone

Lithothamnium funafutiense Foslie 

Lithophyllum moluccense Foslie

? sp.

Porolithon craspedium (Foslie) Foslie 

Goniolithon frutescens Foslie 

Lithoporella melobesioides Foslie 

Amphiroa sp. C 

Halimeda segments

CORRELATION

The accompanying tables 3-5 compare the Eocene, 

Miocene, and Mariana Limestone floras of Guam and 

Saipan.

Eocene. It will be noted that all the Eocene species 

identified from the Alutom Formation on Guam were 

found in Saipan. There most of them occurred in both 

the Densinyama and Matansa Formations, and a few 

also occurred in the lower Hagman Formation. An 

unusual feature of the Guam flora is the scarcity of 

Archaeolithothamnium, which normally is abundant in 

the Eocene floras.

TABLE 3. Stratigraphic distribution of Eocene algae on Guam 

and Saipan

[Saipan data from Johnson, 1957, p. 212, table 2]

Species

Archaeolithothamnium chamorrosum 

Johnson..... _ . ___ _____ ...

cf. A. liberum Lemoine ...............

oulianovi Pfender... _________ .

crispithallus Johnson __ ______

cymbicrustum Johnson. .. __ ......

moreti Lemoiue.. . 

cf. L. nanosporum Johnson and 

Ferris __ . ______ _ ___ . ...

waUisium Johnson and Tafur... .....

sp. A... ____ ______ . _. _

Lithophyllum oeatum (Capeder) Lemoine.

sp. A... ________ . ...

melobesioides (Foslie) Foslie-.

Melobesia cuboides Johnson ___ . ....

Janiasp. _______________ .

Arthrocardial sp ___ . ______ . ....

prisca Johnson .......................

Cymopolia cf . C. pacifica Johnson . . . __

Halimeda sp..... __ _.

Perforating algae ..........

Guam

Alutom Formation

X

X

X

X

X

X

v

X

X

X

X

Hagman Formation

X

X

Saipan

Densinyama Formation

X

X

v

X

X

v

v

v

v

Matansa Limestone

X

X

X

v

X

V

X

V

v

v

Miocene. All the Miocene limestones of Guam 

carried some algae, but algae were most abundant in the 

Maemong and least common in the Barrigada. It is

rather surprising to note that the algal flora of each 

formation is distinct, very few species occurring in more 

than one formation. The Maemong has the richest 

Miocene flora the author has seen from the tropical 

Pacific.

Pliocene and Pleistocene. In the Mariana Limestone, 

algae were found only in the reef and fore-reef facies. 

All the species identified are Recent species. All were 

found in the Mariana Limestone of Saipan, which also 

included a number of additional species.

TABLE 4. Stratigraphic distribution of Miocene algae

on Guam and Saipan 

[Saipan data from Johnson, 1957, p. 212-213, table 2]

Species

sp. G.. 

prelichenoides Lemoine. 

SD. C.-._ ___ .--. ___ - -- - 

Guam

Maemong Limestone Member

X

X

X

v

X

X

X

X

X

X

X

X

X

X

v

Limestone Bonya 

X

X

X

X

X

Alifan Limestone

X

X

X

y

X

--

X

X

X

1«J

J

03 -§

Ml

M

--

X

Saipan

Tagpoehau 

Limestone

Transitional

--

Tuffaceous

X

X

CD

1

>> 

3 

%

X

X

Rubbly facies Equigranular

X

X-

----
G6 GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

TABLE 4. Stratigraphic distribution of Miocene algae 

on Guam and Saipan Continued

Species

problematicum Johnson n. sp_. ___ - __ -- __ .

saipanense Johnson...... __ _--- __ __ .- .. __

sp. B__ _________ _____________ .......

Amphiroa anchiverricosa Johnson and Ferris -- ___ ...

cf. A. regularis Johnson and Ferris. ._ _ -------------

cf. A. verricosa Kiitzing. ....._.... . .. .

Corallina neuschelorum Johnson--.. _ _ _ .. ---------

Guam

Maemong Limestone Member

X 

v

v

X

v

Limestone Bonya 

X

v

Alifan Limestone

X

X

X

Barrigada Limestone

X

X

X

Saipan

Tagpochau 

Limestone

"3 

|

£

Tuffaceous

__

 S 

>>

TH 

03

S

X

Rubbly facies Equigranular

X X

X --

TABLE 5. Algae of the Mariana Limestone on Guam and Saipan

[Saipan data from Johnson, 1957, p. 212-213, table 2.] 

Species Guam 

Archaeolithothamnium megasporum Johnson _ _ _ _ _ ____

puntiense Airoldi________--_---_-___-___ ____

Lithothamnium cf. L. aucklandicum Foslie_______ ____

ef. L. engelhartii Foslie___________________ ____

funafutiense Foslie _ ______________________ X

Saipan 

X 

X 

X 

X 

X

lichenoides (Ellis and Solander) Foslie _______ ____ X

tanapagense Johnson____________________ ___

madagascariense Foslie__-_--______-______ ___

Lithophyllum stefaninii Airoldi_________________ ___.

expansum Philippi_______________________ ___

cf. L. racemus (Lamarck) Foslie___________ ___.

megacrustum Johnson and Ferris___________ ___.

yendoi Foslie-___________________________ ___.

moluccense Foslie ________________________ X

X 

X 

X 

X 

X 

X 

X 

X

ef. L. rovertoi Airoldi- ____________________ ____ X

Goniolithon frutescens Foslie ___________________ X ?

Porolithon craspedium (Foslie) Foslie-__________ X X

onkodes (Heydrieh) Foslie_________________ ____ X

Lithoporella melobesioides (Foslie) Foslie ________ X X

Dermatolithon sp__-__-___-__--_--_--_-__-__-_ ____ X

Amphiroa foliacea Lamouroux_________________ ____ X

fragilissima (Linneaus) Lamouroux________ ____ X

sp_____._______________________________ X X

Jania sp-___-________-_-_-_-__-__-__-_____-_ ____ X

Halimeda segments_________________________ X X

Previous studies of the fossil algae from the Pacific 

area have shown that on most of the islands that have 

been studied to date, there are well-developed Eocene, 

Miocene, and Pleistocene floras which are very distinct.

Stratigraphically, they are separated by unconformities 

representing considerable lengths of time. The Eocene 

flora appears to have been the most widespread geographically. It contained identical species whose habitat 

was from the Mediterranean region to the Marshall 

Islands and from Saipan southward to the East Indies. 

The Miocene flora had a similar although slightly less 

extensive distribution. The Pleistocene flora was more 

restricted and is almost identical with the Recent flora, 

except that it appears to contain a larger number of 

species. This may, however, only reflect a lack of 

knowledge of the Recent floras, which have not been 

thoroughly studied.

Tables 3 and 4 show the composition and known 

distribution of the Eocene and the Miocene floras. 

It will be noted that these floras consist mainly of 

genera which have survived to the present day, but 

there is some difference in their relative importance. 

In most regions Archaeolithothamnium is most abundant in the Eocene, is still abundantly represented in 

the Miocene but is rare in Recent floras. Lithothamnium was more commonly represented in the early 

Cenozoic and has gradually decreased in importance in 

warmer waters as the Cenozoic progressed. Lithophyllum was common in the Eocene but has become 

more important and varied with the passage of time. 

At the present, Lithophyllum has its greatest development in the tropics, whereas Lithothamnium grows 

best in colder waters. Mesophyllum appears to have 

reached its greatest development during the Miocene. 

Porolithon and Goniolithon are abundant in and characteristic of the late Pliocene, Pleistocene, and Recent. 

Goniolithon appears in the Miocene. Specimens attributed to Porolithon have been recorded from the late 

Miocene. Representatives of these two genera, however, were not abundant until middle or late Pliocene 

times, and their abundant occurrence in the limestones 

seems always to indicate a Pleistocene or Recent age.

The articulated corallines occur throughout the Cenozoic and are locally abundant even in the Eocene rocks. 

They are represented in the Eocene floras by the genera 

Amphiroa, Corallina, and Jania. Members of the last 

two genera appear to be similar to Recent forms except 

for minor specific differences. However, most of the 

members of the Eocene Amphiroa were built of cell 

layers of equal length. This continued to be true until 

about the end of the Miocene when alternate layers of 

different lengths became more and more abundant, a 

characteristic feature of virtually all the Pleistocene 

and Recent species.

LOCALITIES

Localities where the algae were collected are given 

on the sample-collecting locality map (fig. 1). The 

localities referred to in this report are listed as follows.
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM

Uu 1

FIGURE 1. Map of Guam showing sample-collecting localities of calcareous algae.
GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

Collecting localities for algae samples Collecting localities for algae samples Continued

D12-1

Ed 3-1

Ed 4-1

Ed 5-1

Ef 2-1

Eh 3-3

Eh 3-8

Ek 7-2

Fd 1-1

Fd4-l

Fi3-2 

F13-4

F15-1

Fi 6-1

Fi 6-4

Fi 6-5

Fi 6-6

Fi 6-7

Fj 2-1

Fj 2-4

Fji2-5

Fk4-l

Fk4-2

Fk4-3

Fk4-4

Fk4-7 

Fk4-8

Fk4-9

Fk4-ll

Gi 1-1

Gi 1-3

Gi2-7

Gi4-l

Gi 4-2

Gj 1-1

Gj 3-1

Gj 4-1

Gj 4-4

Gj 7-2

Gj 10-1

GMH l(d. 

30-35)

GMH 3(d.

10-15)

GMH 7

GMH 11

Hi 3-4

Hi 3-5

Hi 3-6

Hi 5-1

Hi 5-2

Hi 5-3

Hi 10-1

Hi 12-2

Hi 12-3 -

Hn 7-1 

Hn7-2

Hn7-3

Ih 5-6

Ih 14-1

Ih 14-2 li 6-27 Jj 3-1 Ts 16-3

li 6-2 li 6-28 Jj 5-1 Ts 10-4

li 6-8 li 6-31 Jl 2-2 Ts 16-5

li 6-9 li 6-32 Oq 1-1 Ts 16-6

Ii6-13 li 6-33 Ov 7-2 Ts 16-9

li 6-16 li 6-34 Ov 7-3 Ts 16-11

li 6-17 li 6-36 Rx 8-2 Ts 16-12

li 6-18 li 6-37 Ts 9-1 Tt 7-4

li 6-25 li 6-38 Ts 16-1 Uu 1-1

li 6-26 Ji 1-1 Ts 16-2 Agana Reef

Table 6 gives the equivalent field and permanent

catalog numbers of material herein described and

illustrated (first two columns) . The last three columns

apply only to type and figured specimens.

TABLE 6. Field and permanent catalog numbers for fossil algae from Guam

USGS paleobotanlcal 

locality

D891_---._.

D892 __ .__

D892_______

D893.______

D894____.__

D895_______

D896__.____

D897_--____

D898-----__

D899_.____.

D899______.

D900__.___.

D900___.___

D900____.__

D901____.._

D902_______

D903___.._.

D904...__._

D905.______

D906_._____

D907._.____

D908.______

D909.____

D909______.

D909______

D910._____.

D911___

D912 _

D913_______

D914______

D914____

D915._____

D916_____

D916_______

D917.______

D918____._

D919____ _

D919_____

D920_______

D920___

D921____

D922______.

Field No. on 

locality map

Ed 4-1

Eh3-3_____._

Eh 3-3 _____

Eh3-8-_____-

Fdl-l_______

Fi 3-2 _ ____

Fi 3-4. ___ __

Fd4-l_______

Fi5-l_______

Fi6-7______

Fi6-7_______

Fj 2-4. _ .___

Fj 2-4_______

Fj 2-4_ ______

Fj 2-5_______

Fk 4-9.---- _

Cocos Island

Reef. 

Gi !-!__ -___

Gi 2-7_ ______

Gj !-!_______

Gj 4-l_______

Gj 4-4_____-_

Gj 7-2_______

Gj7-2_______

Gj 7-2_______

Hi3-4_______

Hi3-5_____ _

Hi5-l____ _

Hi 12-3_

Hi 10-1______

Hi 10-1___ __

Hn7-l_______

Hn7-2

Hn 7-2_______

Hn 7-3_

li 6-8__._____

li 6-25_ _ _

Ii6-25-_._ _

li 6-26__ _ _

li 6-26_______

li 6-27__ _

Ii6-28____ _

USGS type 

algae number

A721_______

A767 ____

A767_______

A760_______

A755_______

A762_______

A754_______

A778-_.___-

A763_______

A698_ _ ___

A698____._-

A697_____-_

A697_______

A697_______

A703_______

A772_______

A740. _ ___

A753_______

A742_______

A696_______

A780_______

A768-______

A713_______

A713___ __

A735_______

A727_______

A712_______

A720_______

A777_____._

A702b______

A702a__.___

A776_______

A748_ ___

A775____.__

A704_______

A709_______

A719_______

A743_______

A7l4a__ _

A714b_____

A705_______

A711_______

Type of new species

sp.

n. sp.

n. sp.

n. sp.

sp.

Dermatolithon auamensis Johnson n. sp_

Other figured specimens

Do.

Goniolithon miocenicum Johnson n. sp.

Aethesolithon problematicum Johnson n. sp.

Jania guamensis Johnson n. sp.

Lithothamnium bourcarti Lemoine.

Cympolia cf. C. padfica Johnson.

Lithophyllum moluccense f. flabelliformis

Foslie.

Amphiroa anchiverricosa Johnson and Ferris.

Halimeda sp.

Lithoporella sp. A.

Amphiroa anchiverricosa Johnson and Ferris.

Lithophyllum sp. B.

Mesophyllum guamense Johnson n. sp.

Lithophyllum maemongense Johnson n. sp.

Lithothamnium cf. L. peleense Lemoine.

cf. L. araii Ishijima.

Corallina sp. A.

Lithophyllum sp. F.

Corallina sp. A.

Dermatolithon sp. B.

Lithophyllum pseudoamphiroa Johnson n. sp.

Mesophyllum sp. D.

Jania guamensis Johnson n. sp.

Lithothamnium cf. L. araii Ishijima.

Mesovhyllum quamense Johnson n. sp.
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM 

TABLE 6. Field and permanent catalog numbers for fossil algae from Guam Continued

G9

USGS paleobotanical 

locality

D923__.____

D924 _______

D925-------

D925-------

D926.______

D926_______

D926_______

D926__.____

D927-------

D927_______

D927_-_-___

D928_______

D928--_____

D929_______

D929

D930_______

D930_____._

D930-_____

D931_--_-__

D931_______

D932_______

D933_______

D934_______

D935-------

D936_____._

D936_______

D936_______

D937_______

D937_______

D937_______

D938__.____

D939-__-__

D940___ _ _

D940______.

D941_ _ ___

D942_______

D943______.

D944_______

D945__-____

D946______.

D946_______

D946

D946_______

D946_______

D946____ _

D946

Field No. on 

locality map

Ii 6-32_______

li 6-33_-__--_

Ii 6-34____.__

Ii 6-34_-~_---

li 6-36_______

Ii6-36___-___

Ii 6-36_______

Ii 6-36_______

Ii6-37_____._

Ii 6-37_---___

Ii 6-37 

Ii 6-38_______

Ii 6-38 

Ih 5-6_______

Ih5-6__-___-

Ih 14-1______

Ih 14-1------

Ih 14-1______

Ih 14-2______

Ih 14-2______

Ji l-l___ _

Ov 7-2__ ____

Ov 7-3 

Rx8-2_______

Ts 9-l_______

Ts9-l__-____

Ts9-l_ 

Ts 16-1______

Ts 16-l-_ 

Ts 16-1 

Ts 16-2______

Ts 16-3- 

Ts 16-5------

Ts 16-5------

Ts 16-6______

Ts 16-9_-____

Ts 16-12_____

Tt7-4___ 

Uu 1-1______.

Agana Reef_

Agana Reef

Agana Reef

USGS type 

algae number

A722_______

A699_______

A723_______

A745- __

A700_______

A700_______

A700_______

A707_______

A710a_____-

A710a______

A710b_.___

A708_______

A708_______

A731_______

A736.______

A724- _

A729_______

A770_______

A730_______

A730_______

A733_______

A771_______

A732_______

A774_______

A706____.__

A715______-

A737_______

A734_______

A761_______

A765, A766_

A716 _

A733_.___--

A718_______

A764_._____

A701_______

A747_ _ 

A728_______

A769____.__

A781_.____-

A738, A739_

A749__ _ __

A750, A751-

A752_______

A756, A757_

A758, A759_

A741, A782_

Type of new species Other figured specimens

sp. G.

Do.

Lithophyllum cf. L. obliquum Lemoine.

quadrangulum v. welschi Lemoine.

Lithophyllum bonyense Johnson n. sp.

sp. C.

cf . A verricose Kiitzing.

Lithothamnium sp. H.

Lithophyllum aff. L. glangeaudi Lemoine.

alternatum Johnson n. sp.

Amphiroa prefragilissima Lemoine.

Aethesolithon grandis Johnson n. sp.

Lithophyllum alifanense Johnson n. sp.

alifanense Johnson n. sp.

Amphiroa prefragilissima Lemoine.

Lithophyllum sp. G.

Amphiroa cf. A. regularis Johnson and Ferris.

Halimeda sp.

Lithophyllum kotschyanum (Unger) Foslie.

Goniolithon cf. G. fosliei (Heydrich) Foslie.

medioramus Johnson n. sp.

reinboldi Weber von Bosse and Foslie.

reinboldi Weber von Bosse and Foslie.

Lithophyllum moluccense f. pygmaea Foslie.

SYSTEMATIC DESCRIPTIONS

Phyllum RHODOPHYTA (Red algae) 

Family CORALLINACEAE (Coralline algae)

Subfamily MELOBESIOIDEAE (Crustose coralline algae)

The crustose coralline algae typically are strongly 

calcified. They develop a large number of growth 

forms ranging from thin crusts to large branching forms.

Genus ARCHAEOIITHOTHAMNIUM Rothpletz, 1891

Structurally this genus shows the most primitive 

features of any of the Corallinaceae (table 7). It 

includes crustose, mammillate, and branching forms. 

The hypothallus of the crust is formed of curved rows 

of cells. Commonly it is not strongly developed. The 

tissue of the crusts and branches normally appears to

68837© O 63 2

be formed of layers of cells. In some specimens this 

is not very evident. In some branching forms the 

tissue contains rows of cells rather than layers. Faint 

suggestions of growth zones are occasionally seen. The 

sporangia are not collected into conceptacles but are 

isolated in the tissue, commonly in lenses or layers.

The geologic range of Archaeolithothamnium is from 

the Late Jurassic to the Recent. It had its greatest 

development during the Late Cretaceous and Eocene 

but continued abundantly in most regions during the 

Oligocene and Miocene. Since then, it has slowly but 

steadily declined in numbers and variety. Today it is 

represented by about a dozen species. Throughout its 

history, Archaeolithothamnium seems to have been 

restricted to warm marine waters.
GUO GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

TABLE 7. Measurements, in microns, and distribution of species of Archaeolithothamnium from Guam

[Fr,om random sections]

Species

Hypothallus cells

Length Width

Perithallus cells

Length Width

Sporangia

Height Diameter

Localities Age

Division 1. Simple crusts

[Commonly thin. In some instances several thalli superimposed]

taiwanensis Ishijima . .... .

12-15 

11-20 

19-26

n i^

6-11 

9

12-17 

10-11 9-17

9-15 

8-11 8-12 41-60 36-52

Fi 6-1, li 6-32, li 6-36. .

Hn 7-2.. ....................

D12-1, Fd 4-1. .... .

Miocene. 

Miocene (?) 

Miocene.

Division 2. Crusts with warty protuberances or mammillae

11-17 9-12 9-16(22) 9-12 82-135 64-100 Fk4-l, Fk4-2, Fk4-4.._. - Eocene.

Archaeolithothamnium lauense Johnson and Ferris

Archaeolithothamnion lauensum Johnson and Ferris, 1950, B.P.

Bishop Mus. Bull. 201, p. 11, pi. 1, figs. A, D. 

Archaeolithothamnium lauense Johnson and Ferris. Johnson,

1957, U.S. Geol. Survey Prof. Paper 280-E, p. 218, pi. 46,

fig. 7.

Description. Thallus forms thin crust. Hypothallus 

thin or absent; if present, consists of few curved rows of 

cells 12)U-15)U by 11)U-13)U. Perithallus consists of regular compact tissue with cells 12^-17^ by 9/i-15/i. No 

sporangia observed.

Remarks. The Guam specimens are similar to those 

ascribed to this species from Saipan.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Locs. Fi 6-1, li 6-32, and li 6-36.

Archaeolithothamnium cf. A. puntiense Airoldi

Archaeolithothamnion puntiense Airoldi, 1933, Palaeontographia 

Italica, Mem. Palaeont., v. 32, p. 83, pi. 7, fig. 1.

Archaeolithothamnium puntiense Airoldi. Johnson, 1957, U.S. 

Geol. Survey Prof. Paper 280-E, p. 218, pi. 53, figs. 3, 4.

Description. Thallus forms irregular crust. Hypothallus thin, consisting of few curved rows of irregular 

cells 11^-20^ by 6^-11^. Perithallic tissue quite regular, cells 10/i-H^ by SM-HM- No sporangia present.

Remarks. Represented by a single fragment of a 

young thallus that appears to represent the same species 

described under this name from Saipan, although it has 

a more regular perithallic tissue.

Occurrence: Upper Miocene and Pliocene, Alifan Limestone. 

Loc. Hn 7-2.

Archaeolithothamnium cf. A. taiwanensis Ishijima

Archaeolithothamnion taiwanensis Ishijima, 1942, Taiwan Tigaku

Kizi, v. 13, no. 4, p. 120, fig. 2. 

Archaeolithothamnium taiwanensis Ishijimi. Johnson, 1957,

U.S. Geol. Survey Prof. Paper 280-E, p. 218, pi. 46, figs.

4-6.

Description. Thallus forms thin crust, commonly 

covering other organisms. Several thalli may be

superimposed. Hypothallus thin or absent; at most 

a few irregular rows of cells 19,u-26)U long and 9,u wide. 

Perithallus consists of regular rows of rectangular cells 

9/i-17/i by 8/j,-12/j,. Normally vertical partitions are 

more prominent than horizontal ones. Sporangia 

round to ovoid, 41/j,-60/ji by 36^-52^, moderately spaced 

in well-defined layers.

Remarks. The Guam specimens closely resemble the 

material described from Saipan but tend to have more 

rounded sporangia and have slightly longer cells.

Occurrence: Miocene, Maemong Limestone Member of Umatac 

Formation and Alifan Limestone. Locs. Fd 4-1 and Di 2-1.

Archaeolithothamnium saipanense Johnson

Archaeolithothamnium saipanense Johnson, 1957, U.S. Geol. 

Survey Prof. Paper 280-E, p. 220, pi. 38, figs. 1-4, 6.

Description. Thallus develops moderately thick 

crust with mammelons. Tissue regular with regular 

rows of sporangia. Hypothallus thin (14^-53^), consisting of few curved rows of cells 11^-17^ by 9^-12^. 

Perithallus 350^-1,000)U thick, tissue regular, composed 

of rows of rectangular cells with well-defined, regularly 

spaced horizontal and vertical walls, cells 9^-16^ (22)^u 

by Qn-l2fjL. Sporangia elliptical to circular, commonly 

abundant and closely packed, 82^-135^ high and 64/r100)U in diameter.

Remarks. This species is characterized by the poorly 

developed hypothallus, the very regular perithallic 

tissue with small nearly square cells and relatively 

large sporangia. The Guam specimens are identical 

with those described from Saipan.

Occurrence: Upper Eocene, Alutom Formation. Locs. Fk 

4-1, Fk 4-2, and Fk 4-4.

Tribe IITHOTHAMNIEAE 

Genus IITHOTHAMNIUM Philippi, 1837

The genus Lithothamnium is characterized by having 

a tissue formed of many layers of cells which commonly
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM Gil

can be differentiated into a hypothallus and a perithallus. Normally, the hypothallus consists of curved 

rows of cells, but in a few species it has a development 

which is almost similar to the coaxial hypothallus 

characteristic of the genus Lithophyllum. In these 

species the rows of hypothallic cells bend from the 

center both upward and downward and are quite regularly arranged. The perithallic tissue consists of rows 

of cells which are mainly vertical in the crustose forms. 

This is in marked distinction to the horizontal layers of 

cells which characterize the genus Lithophyllum. The 

conceptacles normally are fairly large and have a roof 

pierced by many apertures for the escape of spores. 

Fossil representatives of the genus have been reported 

from rocks as old as Late Jurassic, but they did not 

occur abundantly until Late Cretaceous times. From

the Eocene to the Recent they have been numerous and 

widespread, being found in almost all seas, though with 

the passage of time they have become more and more 

restricted to the cooler and cold waters, so that today 

their greatest development is in the cool temperate and 

polar waters.

Lithothamnium is abundantly represented in the 

Cenozoic limestones of Guam. Seventeen species were 

recognized.

For convenience, the species from Guam are arranged 

in four divisions based on growth habit: division 1, 

simple crusts; division 2, free crusts; division 3, crusts 

with warty protuberances or mammillae; and division 

4, strongly branching forms.

The dimensions and distribution of the species occurring on Guam are shown in table 8.

TABLE 8. Measurements, in microns, and distribution of species of Lithothamnium from Guam

[From random sections]

Species

Hypothallus cells

Length Width

Perithallus cells

Length Width

Conceptacles

Diameter Height

Localities Age

Division 1. Simple crusts

[Commonly thin, many may occur superimposed]

11-14

n 90 f ^9t

14-25

12-18

8-11

18-24

21-23

8-13

12-13

10-15

9 17

11-15

8-11

7-11

9-11(13)

7 10

(8)10-16

12-20

12-17

7-14

7 11

10-18

9-15

13-16

8 10

8 14

8-11

10-13

7 10

Q 1^

6-11

6-11

8-13

8-10

220-298

409-475

450-550

?

46-57

121-127

Fk 4-2....... ... ... 

Gj 1-1. 

GMH-3 (d. 10-15) .

Fi 6-7, li 6-33, li 6-36 

Ts 16-6 

Hi 10-1 

Ts 16-1 

Fk 4-11.... 

116-36 

Do.

Do.

Do.

Do.

Division 2. Free crusts

7-12

9-16

6-8

8-11

8 10

8-11

6-9

7-10

222-270 Fk 4-2, Fk 4-3.- 

Fk 4-2, Fk 4-3, Fk 4-11.. Do.

Division 3. Crusts with warty protuberances or mammillae

sp. H ................. ......... ...................

11-25

14-15

22-29

11-18

8-10

10-13(17)

12-19

9-14

14-21

12-18

9-12

11-16

Hi 10-1, li 6-27 

Hi 10-1, li 6-27 ... ...

Ts 9-1... 

Do.

Do.

Division 4. Strongly branching forms

10-25

14-21

8-14 250-510

450

Fk 4-2... .... 

li 6-36.. 

Eocene.

Miocene.

Division 1 Simple crusts 

Lithothamnium cf. I. aggregatum Lemoine

Lithothamnion aggregatum Lemoine, 1939, Mat. Carte g6ol. de 

1'Algerie, ser. 1, Paleont., no. 9, p. 66, 79, pi. 1, figs. 12, 27.

Lithothamnium cf. L. aggregatum Lemoine. Johnson, 1957, U.S. 

Geol. Survey Prof. Paper 280-E, p. 221, pi. 40, figs. 2, 4.

Description. Thallus forms thin crust. Hypothallus 

150^-190^ thick, consisting of curved rows of rounded 

rectangular cells 11^-16^ by 7/1-14^. Perithallus 70^- 

300M thick, regular tissue with well-defined vertical and 

horizontal partitions, rectangular cells 8/J.-17/J. by 9^- 

14/j,. No conceptacles present.

Remarks. Guam specimens are identical with those 

described under this name from Saipan. Without 

knowledge of the conceptacles, it does not seem desirable 

to give this form a specific name.

Occurrence: Upper Eocene, Alutom Formation. Loc. Fk 4-2. 

Lithothamnium bonyense Johnson n. sp. 

Plate 1, figure 6

Description. Thallus develops as a rather irregular 

crust. Hypothallus absent or represented by few 

curved rows of cells; hypothallus poorly preserved with
G12 GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

cells about 12^-13/i wide (lengths not accurately measurable). Perithallus 450^-750^ thick. Tissue quite 

regular, giving appearance of well-defined horizontal 

layers of cells as well as vertical rows. Conceptacle 

chambers numerous, small 220^-298^ in diameter.

Remarks. This crustose species is characterized by 

its poorly developed hypothallus, its unusually regular 

perithallic tissue, and its small conceptacles and cell 

dimensions. The cell dimensions and regular perithallic 

tissue suggest L. lecroixi Lemoine from the Miocene of 

Martinique, but L. lecroixi is a branching or mammillated form and has larger conceptacles.

Occurrence: Lower Miocene, Bonya Limestone. Loc. Gj 1-1 

(D906).

Figured specimen: Holotype A696.

Lithothamnium bourcarti Lemoine 

Plate 1, figure 5

Lithothamnion bourcarti Lemoine, 1923, Soc. g6ol. France Bull., 

ser. 4, v. 23, p. 277-278, fig. 3.

Description. Thallus forms thick mammillated crust. 

Hypothallus thin, secondary developments of hypothallic scar also present, cells 29^-48^ by lO/r-15/*. 

Perithallic tissue of mammillae shows numerous growth 

zones, cells 11^-17^ by 10^-13^- Conceptacle chambers wide and flat, 400^-594^ in diameter.

Remarks. The specimens from Guam closely fit the 

material originally described by Madame Lemoine from 

the Miocene (Burdigalian and lower Helvetian) of 

Albania. The cells of the Guam specimens average a 

little larger but fall within the size range recorded for 

the type.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Locs. Fi 6-1 and Fj 2-4 (D900). 

Figured specimen: A697.

Lithothamnium funafutiense Foslie

Lithothamnion funafutiense Foslie, 1900a, K. norske vidensk.

selsk. Skr., no. 1, p. 5. 

Foslie and Printz, 1929, K. norske vidensk. selsk. mus.

Mon., p. 41, pi. 12, figs. 3-4. 

Lithothamnium funafutiense Foslie. Johnson, 1957, U.S. Geol.

Survey Prof. Paper 280-E, p. 222, pi. 54, fig. 3.

Description. Thallus forms irregular crust. Hypothallus poorly developed, cells 11^-20(32) p by 9^-17/*. 

Perithallus 130^-450^ thick, dense tissue of small rectangular cells 7^-14^ by 7/j,-l Q/J,. No conceptacles 

present.

Remarks. The few specimens from Guam fit Foslie's 

rather loose description quite well. They differ from 

the specimens attributed to this species from Saipan 

by showing some hypothallus, which, however, is 

present in Foslie's type specimen.

Occurrence: Pleistocene, Mariana Limestone. Loc. GMH-3 

(d. 10-15).

Lithothamnium maemongense Johnson n. sp. 

Plate 1, figures 1-3

Description. Thallus forms crust with well-developed hypothallus and perithallus. Hypothallus 

150^-200^ thick, composed of rows of cells, some of 

which curve upward and others downward from near 

middle; cells rectangular 14^-25^ by 11^-15^. Perithallus 125^-160^ thick, very regular tissue of nearly 

square cells 7/j,-l I/JL by 9^-13^- Conceptacles wide and 

flat, circular in plan, reniform in vertical sections, 

450^-550^ in diameter.

Remarks. This species resembles L. ladronicum 

Johnson in growth habit, general appearance, and size 

of the perithallic cells, but differs in size and shape of 

the hypothallic cells and in having a much more regular 

perithallic tissue.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Locs. Fi 6-7 (D899), li 6-33 (D924), and 

li 6-36 (D926).

Figured specimens: Holotype A698. Also figured: A699 and

A700.

Lithothamnium alifanense Johnson n. sp.

Plate 1, figure 7

Description. Thallus crustose, fairly thick in some 

specimens, well-developed hypothallus and perithallus. 

Hypothallus, 80^-140^ thick, consists of curved rows of 

cells 12/4-18^ by 80-110. Perithallic tissue 8000- 

1,2000 thick, quite regular, with suggestions of thin 

growth zones; cells 100-180 by 60-1 10. Conceptacles 

unknown.

Remarks. In all dimensions, this species resembles 

L. betieri described by Lemoine from the Pliocene of 

Algeria (except the cells of Guam specimens average 

slightly less in width). L. betieri develops as a strongly 

mammillated crust, whereas L. alifanense appears to 

form rather smooth crusts.

Occurrence: Upper Miocene, Alifan Limestone. Loc. Ts 16-6 

(D941).

Figured specimen: Holotype A701.

Lithothamnium cf. L. peleense Lemoine 

Plate 2, figure 1

Lithothamnion peleense Lemoine, 1917, Soc. g6ol. France Bull., 

ser. 4, v. 17, p. 268, fig. 16.

Description. Thallus forms thin crust. Hypothallus 

1180-1300 thick, composed of curved rows of cells 

which continue vertically into perithallus with little or 

no change. Hypothallic cells 80-1 10 by 70-110. 

Perithallus consists of slightly sinuous vertical rows of 

cells having pronounced vertical walls and faint horizontal partitions, cells 90-150 by 60-110. No conceptacles observed.

Remarks. This form closely resembles L. peleense in 

growth habit and character of perithallic tissue and in
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM G13

cell dimensions (except that the hypothallic cells of 

L. peleense are longer). Without knowledge of the 

conceptacles of either, it is uncertain whether or not 

the two belong to the same species.

Occurrence: Lower Miocene, Maemong Limestone Member of 

ITmatac Formation. Loc. Hi 10-1 (D914). 

Figured specimen: A702b.

Lithothamnium cf. L. saipanense Johnson

Lithothamnium saipanense Johnson, 1957, U.S. Geol. Survey Prof. 

Paper 280-E, p. 222, pi. 49, fig. 3.

Description. Thallus forms thin slightly irregular 

crust. Hypothallus only slightly developed and not 

well preserved. Perithallus 130/*-185/i thick, cells 

8/t 12/t by 6/t lOju. No conceptacles present.

Remarks. Represented by a single piece of a young 

infertile plant. The perithallic tissue resembles L. 

saipanense Johnson in character and cell dimensions.

Occurrence: Upper Miocene, Alifan Limestone. Loc. Ts 16-1. 

Lithothamnium tagpotchaense Johnson

Lithothamnium tagpotchaensis Johnson, 1957, U.S. Geol. Survey 

Prof. Paper 280-E, p. 223, pi. 37, fig. 7, pi. 39, fig. 7.

Description. Thallus thin, encrusting. Hypothallus 

thin but distinct, cells 18/1-24/1 by 9/1-13/1. Perithallus 

irregular, tissue composed of well-defined rows of cells, 

cross partitions not distinct, cells 13/i-18/i by 7/i-12/i. 

No conceptacles observed in Guam material.

Remarks. Only a few fragments observed in the 

Guam collection. They are similar to the specimens 

described from Saipan.

Occurrence: Upper Eocene, Alutom Formation. Loc. Fk4-ll. 

Lithothamnium sp. G 

Plate 1, figure 8

Description. Thallus develops into thick crust or 

plate 400^-700/1 thick. Hypothallus 100/i-150/i thick, 

composed of curved rows of cells 12/i-23/i by 7/i-14/i. 

Perithallus as much as 600/i thick, with a very regular 

tissue; cells nearly square 8/i-10/i by 8/t-10/t, with welldefined walls and horizontal partitions. Conceptacles 

unknown.

Remarks. This species is quite distinctive with its 

characteristic measurements and very regular perithallic 

tissue. However, with only a couple of specimens to 

study and without knowledge of conceptacles, it does 

not seem desirable to give it a specific name.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Loc. li 6-36 (D926). 

Figured specimen: A700.

Division 2 Free crusts 

Lithothamnium crispithallus Johnson

Lithothamnium crispithallus Johnson, 1957, U.S. Geol. Survey 

Prof. Paper 280-E, p. 223-224, pi. 42, figs. 6-8.

Description. Thallus thin, curved, may branch; apparently attached at first, then growing free. Hypothallus well developed, 75/i-130/i thick consisting of 

curved rows of cells 8/i-14/i by 7/i-12/i. Perithallus 

thin but irregular, thickening considerably around 

conceptacles; cells rectangular 6/i-14/t by 6/r-12/i. 

Conceptacles wide and flattened, 275/i-400/t in diameter.

Remarks. Similar to the specimens described from 

Saipan. A fairly common species in the Guam 

collection.

Occurrence: Upper Eocene, Alutom Formation. Locs. Fk 

4-3 and Fk 4-2.

Lithothamnium sp. A

Lithothamnium sp. A Johnson, 1957, U.S. Geol. Survey Prof. 

Paper 280-E, p. 224, pi. 40 figs. 8-9.

Description. Thallus thin foliate crust that apparently grew unattached or nearly so. Hypothallus 

70/t-175/i thick, well-developed, forming %-% of the 

crust; consisting of curved rows of irregular rounded to 

rectangular cells 9/r-16/* by 8/r-ll/*. Perithallus 90/r170/i thick, fairly regular rows of rectangular cells 

with well-defined vertical walls and poorly marked 

horizontal partitions, cells 8/i-H/i by 7/j-lO/i. Conceptacles unknown.

Remarks. This is the most abundant Eocene form. 

It appears to be the same species indicated as sp. A in 

the Saipan report. However, until the conceptacles 

are known, it does not seem wise to name it specifically.

Occurrence: Upper Eocene, Alutom Formation. Locs. Fk 

4-2, Fk 4-3, and Fk 4-11.

Division 3 Crusts with warty protuberances or mammillae

Lithothamnium cf. L. araii Ishijima

Plate 1, figure 4; plate 2, figure 2

Lithothamnium araii Ishijima, 1954, p. 26, pi. 8, figs. 3-4; pi. 9, 

figs. 1-3.

Description. Thallus forms irregular crust. Hypothallus slightly developed, consists of curved rows of 

cells 1 l/i-25/i by ll/i-18/i- Perithallic tissue moderately 

regular but with numerous growth zones; cells 12/t-19/t 

by 12/i-18/i- No conceptacles present.

Remarks. Represented in the Guam collections by 

only a few infertile specimens. The cell dimensions 

and general character of the tissue of these are very 

similar to Ishijima's species from the Miocene of 

Japan, but without a knowledge of the conceptacles, 

the two forms cannot be definitely said to be identical.

Occurrence: Lower Miocene, Maemong Limestone Member 

of Umatac Formation. Locs. Hi 10-1 (D914) and li 6-27 

(D921).

Figured specimens: A702a, and A705.
G14 GEOLOGY AND HYDROLOGY OP GUAM, MARIANA ISLANDS

Lithothamnium cf. I. crispatum Hauck

Lithothamnion crispatum Hauck, 1878, Botanische Zeitschr., v.

28, p. 289, pi. 3, figs. 1-4. 

Lignac-Grutterink, 1943, Geol. mijnb. genootsch. Nederland en Kolonien Verb., Geol. ser., v. 113, p. 288, fig. 4. 

Lithothamnium cf. L. crispatum Hauck. Johnson, 1957, U.S.

Geol. Survey Prof. Paper 280-E, p. 224, pi. 48, fig. 4.

Description. Thallus thick irregular crust. Hypothallus poorly developed, few curved rows of irregular 

cells 14/1-1 SM by 8/*-10M. Perithallus 300/1-600/1 thick 

with irregular growth zones, cells 9/t-12/t. No conceptacles observed.

Remarks. Several infertile specimens, which closely 

resemble the material from the East Indies and from 

Saipan, were observed.

Occurrence: Lower Miocene, Maemong Limestone Member 

of Umatac Formation. Locs. Hi 10-1 and li 6-27.

Lithothamnium sp. H 

Plate 2, figure 4

Description. Thallus forms thick irregular crust, 

possibly with knobs or mammillae. Hypothallus 

100/t-150/t thick, almost coaxial; strongly curved rows 

of cells; cells 22/J-29/* by 10/^-13 (17) A*. Perithallus 

500/t-l,000/t thick with pronounced growth zones; 

tissue fairly regular with clearly defined vertical cell 

rows, cross partitions well developed and moderately 

regularly spaced; cells 14/t-21/t by ll/t-16/i. Conceptacles unknown.

Remarks. This species has cell dimensions quite 

different from any previously described late Miocene 

or Pliocene species of Lithothamnium. It somewhat 

suggests L.^araii Ishijima but has a much better 

developed hypothallus and forms appreciably thicker 

crusts.

Occurrence: Upper Miocene, Alifan Limestone. Loc. Ts 

9-1 (D936).

Figured specimen: A706.

Division 4 Strongly branching forms 

Lithothamnium marianae Johnson

Lithothamnium marianae Johnson, 1957, U.S. Geol. Survey Prof. 

Paper 280-E, p. 226, pi. 41, figs. 1-3.

Description. Thallus develops bifurcating branches. 

Hypothallus absent or poorly developed. Branches 

composed of pronounced lenticular growth zones 

containing slightly curved rows of cells, rectangular 

and ranging considerably in size, both within a zone 

and between rows; cells 10/t-25/i by 8/t-14/t. Conceptacles abundant, 250/H510/t in diameter and 150/t180/t high.

Remarks. This is the only branching species of 

Lithothamnium observed in the Eocene of Guam.

Occurrence: Upper Eocene, Alutom Formation. Loc. Fk 4-2.

Lithothamnium sp. F 

Plate 2, figure 6

Description. Thallus forms short thick branches. 

Hypothallus unknown. Branches show numerous irregular growth zones; cells rectangular with welldefined walls and partitions 14/t-21/* by ll/t-15/t in 

slightly oblique section. Conceptacle chambers about 

450/i in diameter.

Remarks. Represented by a single well-preserved 

fragment in the collection studied. The nearest described Miocene species is L. mirabile Conti. A somewhat similar specimen was described from Saipan. 

However, both of the specimens represent oblique 

sections of fragments so no specific name is proposed.

Occurrence: Lower Miocene, Maemong Limestone Member 

of Umatac Formation. Loc. li 6-36 (D926). 

Figured specimen: A707.

Genus MESOPHYLLUM Lemoine, 1928

Structurally this genus lies between Lithothamnium 

and Lithophyllum, having a tissue quite similar to 

Lithophyllum and multiple apertured conceptacles resembling those of Lithothamnium. The genus contains 

both crustose and branching forms.

The basal hypothallus generally is formed of layers 

of cells, but in a few species this arrangement is absent 

or only poorly developed. The tissue of mammillated 

crusts or branches is composed of layers of cells and 

normally shows pronounced growth zones. These 

may be lenticular in branching forms. The conceptacles of sporangia have many apertures in the roof 

for the escape of spores.

The known geologic range of the genus is from Eocene 

to Recent, with probably the greatest development 

during the Miocene.

Mesophyllum commune Lemoine 

Plate 2, figure 3

Mesophyllum commune Lemoine, 1939, Mat. Carte ge"ol. de 

1'Algerie, ser. 1, Paleont., no. 9, p. 86. figs, 55-57.

Description. Thallus develops short, thick branches 

probably from basal crust. Branches composed mainly 

of a perithallic tissue showing pronounced lenticular 

growth zones, each formed of 6-10 layers of rectangular 

cells ll/t-15/t by 7/t-10/t. Conceptacles numerous, 

340/t-^25/t in diameter and 145/t-180/t high. One
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM G15

specimen showed conceptacles filled with sporangia 

45/1-54/1 high and 18/1-29/1 in diameter.

Remarks. The material from Guam exactly fits the 

description given by Lemoine (1939) for the type from 

the Miocene of Algeria. It differs from M. guamense 

Johnson n. sp. by having smaller cells and conceptacles 

and shorter wider branches.

Occurrence: Lower Miocene, Maemong Limestone Member o^ 

Umatac Formation. Loc. li 6-38 (D928). 

Figured specimen: A708.

Mesophyllum grande Johnson n. sp.

Plate 2, figure 5

Description. Thallus consists of thick moderately 

long branches of perithallic tisgue with pronounced 

growth zones, wide and gently arched, containing 10-16 

layers of rectangular to rounded cells 15^-17/1 high 

and 9ju-12ju wide. Conceptacles large, wide, and terminal, with diameters of 720^-876ju.

Remarks. This species has unusually large conceptacles. Only one other branching form with such large 

conceptacles has been described. M. laffittei Lemoine 

(1939). M. grande differs from M. laffittei in cell 

dimensions and in having a much more regular tissue.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Loc. li 6-8 (D918). 

Figured specimen: Holotype A709.

Mesophyllum guamense Johnson n. sp.

Plate 2, figure 7; plate 3, figures 6, 7

Description. Thallus develops moderately long fairly 

thick branches, having a thick central part and thin 

outer layers. Both show pronounced rather irregular 

growth zones with tissues formed of layers of cells. 

Central area 800/^-1,000^ in diameter with cells 17/1-26^ 

long and 9ju-16ju wide. Marginal layers up to 230^ 

thick, cells 9/1-16^ by S/i-llju. Conceptacles 560^- 

590ju in diameter and 230^-246/1 in height.

Remarks. The long thick branches and relatively 

large conceptacles characterize this species. It is close 

to M. savornini Lemoine but differs by developing 

longer more spinelike branches and has less of a basal 

crust. Both forms have cells of about the same size 

and relatively large conceptacles.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Locs. Hi 3-5 (D911), li 6-28 (D922), 

li 6-37 (D927), and li 6-38.

Figured specimens: Holotype A710a. Also figured: A711 and 

A712.

Mesophyllum pacificum Johnson

Mesophyllum pacificum Johnson, 1957, U.S. Geol. Survey Prof. 

Paper 280-E, p. 226, pi. 52, fig. 7.

Description. Thallus formed of long narrow spines 

or branches having pronounced highly arched growth 

zones, each containing 10-12 layers of cells 11^-19^ by 

7ju-13ju. Conceptacles abundant and terminal, 215/i370ju in diameter and 165ju-200ju in height.

Remarks. This is similar to the species described 

and illustrated from Saipan.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Locs. Hi 12-2 and li 6-36.

Mesophyllum savornini Lemoine

Mesophyllum savornini Lemoine, 1939, Mat. Carte geol. de

FAlgerie, ser. 1, Paleont., no. 9, p. 83, figs. 43-46. 

Johnson, 1957, U.S. Geol. Survey Prof. Paper 280-E, p. 227, 

pi. 52, fig. 8.

Description. Thallus forms crust with warty protuberances or short, stubby branches. Basal hypothallus 

absent on Guam specimens. Tissue strongly developed, 

lenticular growth zones; regular rows of cells, showing 

considerable range in length, both in different layers 

and from center to margin of single layer; cells 13/^-24/4 

by 8/*-l2ju. No conceptacles present.

Remarks. Represented in the Guam collection by a 

single specimen that in cell dimensions and character 

of tissue resembles both the type species and the material from Saipan attributed to this species.

Occurrence: Miocene, Alifan Limestone. Loc. Gj 10-1.

Mesophyllum sp. C 

Plate 3, figure 1

Description. Thallus develops long, slender branches 

190/1-850/4 thick, pronounced lenticular growth zones of 

12-15 layers of rectangular cells 18ju-26ju by llju-18ju. 

Marginal perithallus absent or worn off the specimens 

observed. No conceptacles present.

Remarks. Cell dimensions of this form differ from 

any previously described Miocene species. It does not 

seem wise, however, to give it a specific name without a 

knowledge of the conceptacles.

Occurrence: Lower Miocene, Bonya Limestone. Loc. Gj 7-2 

(D909).

Figured specimen: A713.

Mesophyllum sp. D. 

Plate 3, figure 8

Description. Thallus develops long moderately wide 

branches, pronounced strongly arched growth zones of 

17-23 layers of rectangular cells 22/*-32/* high, and 

ll/j-16/* wide. Moderately developed marginal perithallus consists of layers of cells 19/Z-26/* high and 

ll/*-13ju wide. No conceptacles present.
G16 GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

Remarks. This form is quite similar to sp. C but 

forms longer and wider branches which have a moderately developed marginal perithallus. The cells of the 

medullary hypothallus in this species are appreciably 

longer than in sp. C.

Occurrence: Lower Miocene, Maemong Limestone. Member 

of Umatac Formation. Loc. li 6-26 (D920). 

Figured specimen: A714a.

Tribe IITHOPHYLLEAE 

Genus LITHOPHYLLUM Philippi, 1837

In this genus the tissue is clearly differentiated into 

hypothallus and perithallus. The basal hypothallus 

characteristically is coaxial, although in a few species 

it is reduced to a few irregular or curved rows of cells. 

The medullary hypothallus of the branches is also 

coaxial. Normally the perithallus is formed of layers 

of cells, very regularly arranged. However, a few species are known which have a perithallus composed of 

rows of cells, similar to the perithallus of Lithothamnium.

The sporangia are collected into conceptacles which 

are pierced by a single large aperture in the roof for 

the escape of spores.

The genus is represented in the Cenozoic by more 

than a 100 species. It is the most important genus 

of coralline algae in the warm seas today. From it 

have developed the genera Goniolithon and Porolithon 

which are also very important in tropical waters today. 

Twenty-one species are described from the Guam 

collections.

For convenience in study, the species found on Guam 

are arranged in four divisions, which are based on 

their habit of growth.

Division 1 Simple crusts.

Division 2 Crusts free (unattached) or nearly free. 

Division 3 Crusts with warty protuberances or mammillae. 

Division 4 Strongly branching forms.

The dimensions and distribution of the species found 

on Guam are shown in table 9.

TABLE 9. Measurements, in microns, and distribution of species of Lithophyllum from Guam

[From random sections]

Species

Hypothallus cells

Length Width

Perithallus cells

Length Width

Conceptacles

Diameter Height

Localities Age

Division 1. Simple crusts

[Commonly thin, some may grow superimposed]

sp. B- ___ _ _._._ ...

sp. a..-. ..... ......

15-27

16-30

20-27

23-36

15-19

32-48

24-30

Q 1 3

7-16

S 1 1

12-24

7 17

9-22

Q 11

13-18

8 11

7-11

6-15

8-10

1 Q_99

6-8

K in

14-15

Qnft_ift9

46(M80

86-270

135-186

185-193

Hn 7-3, Ts 9-1, Ts 16-1, 2, 5, and 12. ....

Ed 4-1, Fj 2-5, Hi 3-5, Hi 5-1, li 6-25....

li 6-34, li 6-37, li 6-38.. . .... ... .

Ih 14-1.......... ... .- 

116-37.. 

Ek 7-2, Fk 4-3 

Fj 2-4, Hi 3-4.- 

Ts 16-12...... 

Do.

Do.

Do.

Do.

Miocene.

Do.

Division 2. Crusts free (unattached) or nearly free

21-40 10-20 8-20 7-13 160-350 Ed 3-1, Ed 5-1, Qi 1-3, li 6-2, li 6-28,

li 6-32, li 6-34, li 6-36, li 6-37. 

Jj 3-1.

Miocene.

Do.

Division 3. Crusts with warty protuberances or mammillae

sp. E... _ . _ ... _ ... _ ... _____ . _

19-31 9-20 11-20

11-16

8-18

9-16 320 110

Ih 5-6, Ih 14-1, Ihl4-2.._ ... .

Ov7-3- Do.

Division 4. Strongly branching forms

pseudoamphiroa Johnson n. sp .... .......

sp. C-. __ _ _ _ .......... ....... .. _ .

Sp.F. .....................................

fL 41-56

IS 16-24 

/L 32-41

\S 22-25

40-52

23-37

fL 34-58

\S 14-28 

36-63

12-30

18-24

9-14

9-14 

8-13

8-13

8 19

13-21

10-14

6-15

6-14 

13-21

7-15

10-14

Q 11

| 10-15

} 9-16

Q_9A

1 ^ 1 ^

9-16

| 10-20

10-18

9-16

Q 1ft

9-14

7-11

11-15

6-13

8-13

7-11

6-9

OftC_OOl

300-450

200-310

220

275+

66-71

Tsl6-3, Ts 16-1, Jl 2-2.. 

rp« Q_1

Ef2-l 

/Agana Bay, Meritzo Bay, Cocos

i Island, QMH-1 (30-35 ft). 

Fj 2-4, Qj 3-1, li 6-25, Fi 6-5, li 6-26.....

Fi 6-7, Fj 2-1, Gi 1-3, Hi 3-6, Hi 10-1,

li 6-31, li 6-34, li 6-38. 

II 6-37... 

Hn7-2 

Do.

Do.

Do.

Recent.

Recent and Pleis

Miocene.

Do.

Do.

Do.
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM G17

Division 1 Simple crusts (commonly thin), some may grow 

superimposed

Lithophyllum alifanense Johnson n. sp.

Plate 3, figures 3-5

Description. Thallus irregular, crust with welldeveloped coaxial hypothallus and thick perithallus.

Hypothallus 100/4-250/4 thick (average about ISO/*), 

cells 15/4-27/4 by 9/4-13/4. Perithallus 150/4-700/4 thick 

(average about 220/4), fairly regular layers of cells 7/4- 

13(17)/4 by 7/4-11/4. Conceptacle chamber diameters 

300/4-402/4, heights 86/4-270/4.

Detailed dimensions, in microns, of Lithophyllum alifanense Johnson n. sp.

[From random sections. Cleared entries indicate absence of conceptacles]

Locality

Hn 7-3______________________ _

Hn 7-3. ________________________

Ts9-l__--__------______-___-___

Ts 16-1 __-_ ___

Ts 16-2_. _______________________

Ts 16-5____-__________-_____.___

Ts 16-12__ _ _ _ ___

Hypothallus cells

Length

19-27

16-19 

18-24 

15-21 

23-27 

15-18 

15-23 

19-23 

16-21

Width

10-11

7-11 

10-12 

9-11 

9-12 

9-10 

11-13 

9-13 

9-11

Perithallus cells

Length

8-10 

7-17 

8-15 

8-10

9-13

6-11 

9-11

Width

7-10 

9-11 

7-19 

7-11

7-10

6-9 

7-9

Conceptacles

Diameter

600? 

349

320-402

300-385

Height

86

270

150-180

Thickness

Hypothallus

251

110+ 

228 

132 

175-200 

182 

125+ 

125-140 

100-150

Perithallus

194-210

396+ 

192

250-430

150-200 

250-700

Remarks. This is the most abundantly represented 

species in the Alifan limestone. It is close to L. 

fulangasum Johnson and Ferris but differs by having 

smaller hypothallic cells, larger conceptacles, and a 

thicker perithallus. It also resembles closely L. 

bonyense Johnson but has smaller cells. It is similar 

in cell dimensions to L. hanzawaii Johnson from the 

Pleistocene of the Kita-Daito-Jima but differs by having 

much larger conceptacles.

Occurrence: Upper Miocene, Alifan Limestone. Locs. Hn 7-3, 

Ts 9-1 (D936), Ts 16-1, Ts 16-2 (D938), Ts 16-5 (D940), and 

Ts 16-12.

Figured specimen: Holotype A715. Also figured: A716 and 

A718.

Lithophyllum maemongense Johnson n. sp.

Plate 4, figures 1-3

Description. Thallus forms thin crust, may grow 

superimposed on other specimens or species; welldeveloped hypothallus and perithallus tissue. Hypothallus 140/4-225/4 thick, coaxial; arched layers of cells 

16/4-26(30)/4 by 7/4-12(16)/4. Perithallus 150/4-550/4 

thick, commonly about 200/4; regular layers of rectangular cells 9/4-22/4 by 6/4-15/4. Conceptacle chambers 

460/4-480/4 in diameter and 135/4-186/4 high.

Detailed dimensions, in microns, of Lithophyllum maemongensis Johnson n. sp.

[From random sections]

Locality

Ed 4-1 _ ____ 

Fj 2-5_ _-______-_____--_.-______

Hi 3-5--_

Hi 5-1 _____- ______'. _____

li 6-25 ___ __ 

Hypothallus cells

Length

0) 

19-22 

17-26 

19-30 

16-23

Width

(') 

12-16 

10-12 

7-17 8-11

Perithallus cells

Length

10-19 

10-20 

13-22 

9-19 

14-18

Width

6-15 

7-14 

9-13 

7-13 

11-12

Conceptacles

Diameter

460 

480 (2 ) 

(2) 

480

Height

140 

186 (2) 

(2) 

135

Thickness

Hypothallus

124 

205 

140-176 

150

Perithallus

333-527 

437-442 

153 

276-282 

200

1 Hypothallus cells absent.

2 Conceptacles absent.

Remarks. This species differs in the combination of 

cell dimensions and Conceptacle size from any other 

Miocene crustose Lithophyllum. It is similar to .L. 

prelichenoides Lemoine but has larger conceptacles and 

different-sized cells.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Locs. Ed 4-1 (D891), Fj 2-5, Hi 3-5, Hi 

5-1 (D912), and li 6-25 (D919).

Figured specimens: Holotype A719. Also figured: A720 and 

A721.
G18 GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

Lithophyllum cf. L. obliquum Lemoine 

Plate 4, figures 4, 6

Lithophyllum obliquum Lemoine, 1930, Soc. geol. France Bull.,

ser. 4, v. 29, p. 266, figs. 1, 2. 

Lithophyllum cf. L. obliquum Lemoine, 1939, Mat. Carte geol.

de 1'Algerie, ser. 1, PalSont., no 9, p. 97-98, fig. 64; p. 107.

Description. Thallus crustose, well-developed hypothallus and thick perithallus. Hypothallus 125/*-218/i 

thick, coaxial; cell layers not strongly arched; cells 

20M-27/* by 1 l/i-15/i. Perithallus thickness 40(V-45(V; 

vertical rows of cells instead of horizontal layers normal 

for Lithophyllum; cells 9/x-ll/i by 8/i-lO/*. No conceptacles present.

Detailed measurements, in microns, of Lithophyllum cf. L. 

obliquum Lemoine

[From random sections!

Locality

Ii6-34.......

11 6-37. ......

li 6-38. ______

Hypothallus 

cells

Length

20-25 

27-34 

20-27

Width

9-15 

11-17 

11-15

Perithallus 

cells

Length

5-10 

10-14 8-10

Width

7-11 

7-12 9-11

Conceptacles

Absent ...... 

 - do.. .

 -do.- .

Thickness

Hypothallus

218 

218-280 

125-150

Perithallus

350 

477-492 

400-458

Remarks. This species belongs to that division of 

the genus Lithophyllum in which the perithallus contains 

vertical rows of cells rather than horizontal layers. It 

appears to fit Lemoine's description of the type from 

the lower Miocene of Spain and Algeria.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Locs. li 6-34 (D925), li 6-37, and li 6-38 

(D928).

Figured specimens: A708 and A723.

Lithophyllum quadrangulum var. welschi Lemoine 

Plate 4, figure 5

Lithophyllum quadrangulum Lemoine, 1934, Czechoslovakia 

Statniho Geol. Ustavu Ve'stnik, v. 9, no. 5, p. 279, fig. 1.

Lithophyllum quadrangulum var. Welschi Lemoine, 1939, Mat. 

Carte ge'ol. de 1'Algerie, ser. 1, Paleont., no. 9, p. 96, fig. 63.

Description. Thallus crustose, well-developed coaxial 

hypothallus 250M-300/* thick, perithallus same size. 

Hypothallus unusual in that cell layers almost vertical 

rather than strongly arched; unusually large rounded 

cells 23/i-36/i by 16/*-24/i. Perithallus rectangular cells 

13/JL-18/J, high by 13/*-22/* wide. Conceptacles unknown.

Remarks. The Guam specimen closely fits the description given by Lemoine (1939) of the type of the 

variety from the middle Miocene of Algeria and of a 

specimen from Persia.

Occurrence: Lower Miocene, Bonya Limestone. Loc. Ih 14-1 

(D930).

Figured specimen: A724.

Lithophyllum schlangeri Johnson n. sp.

Plate 3, figure 2 

Description. Thallus forms very thin crust, consisting largely of a coaxial hypothallus, overlain by thin 

perithallus, normally with few layers of cells except 

around Conceptacles. Hypothallus 119/^-131^ thick, 

cells 15/*-19/i long and Sfi-lOfi wide. Perithallic cells 

ll/i-15/i by 6(t-8(i. Conceptacles highly arched, 264/i337/i in diameter and 185/^-193^ high.

Remarks. This belongs to the same general type as 

L. prelichinoides which it resembles considerably. It 

differs, however, by having smaller hypothallic cells 

and considerably longer perithallic cells.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatae Formation. Loc. li 6-37 (D927). 

Figured specimen: Holotype A710a.

Lithophyllum sp. A

Lithophyllum sp. A, Johnson, 1957, U.S. Geol. Survey Prof. 

Paper 280-E p. 229, pi. 43, figs. 3, 5.

Description. Thallus forms thin crust with welldeveloped hypothallus and perithallus. Hypothallus 

coaxial, cells ll/t-23/t by 8p-lln. Perithallus consists 

of fairly regular rows of cells 8/j-l IM by 5/jr-Wfj,. No 

Conceptacles present.

Remarks. This represents the same form described 

from the Upper Eocene of Saipan as species A.

Occurrence: Upper Eocene, Alutom Formation. Locs. Ek 7-2

and Fk 4-3.

Lithophyllum sp. B

Plate 4, figures 7, 9

Description. Thallus thin (215/t-310ju), consisting 

only of a well-developed coaxial hypothallus, cells 

rectangular 32^-48^ by 12/t-24ju. Conceptacles unknown.

Remarks. This species closely resembles L. guadrangulum Lemoine (1939, p. 96) from the western 

Mediterranean region but differs by having the coaxial 

hypothallus formed of more strongly curved layers of 

longer cells. It may represent a young form of a species 

close to L. thikombian Johnson and Ferris (1950, p. 17) 

or to L. prelichinoides Lemoine but having longer cells.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Locs. Fj 2-4 (D900) and Hi 3-4 (D910). 

Figured specimens: A697 and A727.

Lithophyllum sp. G 

Plate 4, figure 10

Description. Thallus crustose, consists of welldeveloped coaxial hypothallus and perithallus with 

vertical rows of cells rather than horizontal layers. 

Hypothallus 150/i-270/i thick, cells 24/*-30/*by 16M-22/*. 

Perithallus 300 + M thick, cells 14/t-18/t by 14ju-15/i. 

Conceptacles unknown.
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM G19

Remarks. Kepresented by a single, well-preserved, 

unfertile specimen. This species is closely related to 

L. guadrangulum Lemoine in having large cells, a welldeveloped coaxial hypothallus, and a perithallus with 

rows of cells rather than layers. It differs in cell 

dimensions and by having more strongly arched layers 

of hypothallic cells. It is an interesting and distinctive 

form, but without more material and a knowledge of 

the conceptacles, no specific name is suggested.

Occurrence: Upper Miocene, Alifan Limestone. Loc. Ts 

16-12 (D943).

Figured specimen: A728.

Division 2 Crusts free or nearly free 

Lithophyllum prelichenoides Lemoine

Lithophyllum prelichenoides Lemoine, 1917, Soc. geol. France 

Bull., ser. 4, v. 17, p. 262, figs. 8, 9 [1918].

Lemoine, 1939, Mat. Carte geol. de 1'Algerie, ser. 1, Paleont.,

no. 9, p. 99, figs. 65, 66; p. 107. 

Johnson, 1957, U.S. Geol. Survey Prof. Paper 280-E, p.

229, pi. 49, figs. 1, 2.

Description. Thallus crust or leafy plate, possibly 

free or unattached, well-developed coaxial hypothallus 

may be as thick as SOO/u- Only hypothallus present 

in young specimens, but mature specimens have thin 

perithallus on one or both sides of hypothallus. Perithallus seldom more than eight layers thick except 

around conceptacles, generally less than 250/u thick 

(commonly less than ISO/i). Cells show unusual size 

range; hypothallic cells 21^-40^ by 10^-20^, perithallic 

cells 8^-20^ by 7^-13^. Conceptacles 160^-350^ in 

diameter.

Detailed measurements, in microns, of Lithophyllum prelichenoides Lemoine 

[From random sections. Cleared entries indicate absence of conceptacles]

Locality

Ed 3-1. _________ ___ _

Ed 5-l__________________

Gi l-3----_____________

Gi l-3______________________ _ _

Ii6-2____-______________ _

li 6-2___--_-___________

Ii6-28_____--_--_-_-______ _

li 6-32 ________________

li 6-34______________________ ___

li 6-36____-____________

li 6-37_ _______

Ii6-37.___--_-.______:_ _________

Ii6-37________________

Jj 3-1. _________________________

Hypothallus cells

Length

23-26 

34-41 

24-39 

31-41 

24-33 

20-25 

19-23 

24-30 

18-24 

18-29 

25-30 

21-25 

16-22 

24-31

Width

10-14 

9-13 

10-15 

13-18 

11-14 

11-15 

9-11 

12-18 

9-14 

12-15 

11-18 

13-17 

9-17 

9-16

Perithallus cells

Length

11-17

12-18 

11-15 

11-15 

9-10 

10-12 

15-20 

9-15 

8-11 

11-18 

13-17 

11-15 

10-11

Width

10-13

7-13 

8-13 

8-13 

7-9 

9-10 

9-13 

10-13 

7-11 

10-12 

9-12 

8-12 

5-7

Conceptacles

Diameter

230

161-163 

220-350

250 

263

Height

150

91-113

m l OO

128 

126

Thickness

Hypothallus

80-103 

196-234 

120-142 

196-225 

250-275 

200 

132-159 

173-198 

150 

71-106 

130-224 

92-110

110-141 

162-199

Perithallus

218-280 

Absent 

182-214 

54-94 

150-250 

65-78 

110-166 

230-240 

145-170 

305 

92-130 

95-120 

219-259 

140-152

Remarks. This species occurs abundantly in the 

Maemong Limestone Member. The Guam specimens 

agree in appearance and cell dimensions with the material previously described by Lemoine from Algeria and 

by Johnson from Saipan.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Locs. Ed 3-1, Ed 5-1, Gi 1-3, li 6-2, 

li 6-28, li 6-32, li 6-34, li 6-36, and li 6-37. Lower Miocene, 

Bonya Limestone. Loc. Jj 3-1.

Division 3 Crusts with warty protuberances or mammillae

Lithophyllum bonyense Johnson n. sp.

Plate 4, figure 8; plate 5, figures 1, 2

Description. Thallus forms irregular crust with low 

mammillae composed of well-developed coaxial hypothallus and irregularly developed perithallus. Hypothallus 150M-350M thick, normally about 300/u, cells 

19/u-31/u by 9/U-20/U- Perithallus may be more than 

GOO/i thick, cells 11^-20^ by 8^-18^. Conceptacles 

not present.

Detailed measurements, in microns, of Lithophyllum bonyense 

Johnson n. sp.

[From random sections]

Locality

Ih5-6-.---__-

Ih 14-1(5)-.. 

Ihl4-l(6)-._ 

Ihl4-2_-_.-_.

Ih 14-2. -_-_-.

Ih 14-2(5) ____

Hypothallus 

cells

Length

19-28 

17-27 

21-27 

30-31 

20-27 

19-27

Width

9-14 

10-18 

13-15 

11-16 

14-20 

12-16

Perithallus 

cells

Length

12-20 

11-14 

13-16 

11-18 

15-19 

15-20

Width

11-14

8-11 

10-13 

11-12 

13-16 9-14

Conceptacles

Absent __ 

...do -

...do... ... . 

...do .

...do .

...do.......

Thickness

Hypothallus

150-200 

250-275 

300-350 

250-275 

300± 

300+

Perithallus

500-650 

300-500 

250-350 

75+ 

300-535 

Up to 300

Remarks. This is the most abundant species found 

in the Bonya limestone. It is strongly suggestive of 

L. prelichenoides Lemoine but differs by having larger 

cells, especially in the perithallus, a thicker hypothallus, 

and well-developed irregular perithallus. The cell 

dimensions are about the same as in L. albanense 

Lemoine, but the two forms differ in the tissue structure. L. bonyense has a coaxial hypothallus and a
G20 GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

thick perithallus composed of regular layers of cells. 

In L. albanense the cells are not in regular layers in 

either the hypothallus or the perithallus.

Occurrence: Lower Miocene, Bonya Limestone. Loos. Ih 5-6 

(D929), Ih 14-1 (D390), and Ih 14-2 (D931).

Figured specimens: Holotype A729. Also figured: A730 and 

A731.

lithophyllum sp. E

Plate 5, figure 4

Description. Fragment apparently representing outer 

part of mammillated crust, consisting entirely of perithallic tissue, cells ll/x-16/x by 9/x-16/x arranged in regular layers with unusually thick walls separating the 

layers; vertical partitions distinct and quite regularly 

spaced. A conceptacle chamber has diameter of 320/x 

and height of 110/x, shows large single aperture.

Remarks. In growth habit and character of the perithallic tissue, the thick horizontal walls suggest L. 

sphaeroides described by Lemoine from the Burdigalian 

of Albania, but it differs somewhat in cell dimensions. 

The conceptacles of L. sphaeroides are not known.

The Guam species is represented by a single fragment 

which does not show the hypothallus or much of the 

growth form. Consequently it does not seem advisable 

to give it a specific name.

Occurrence: Upper Miocene, Barrigada Limestone. LOG. Ov 

7-3 (D934).

Figured specimen: A732.

Division 4 Strongly branching forms 

lithophyllum alternatum Johnson n. sp.

Plate 5, figures 3, 5, 6

Description. Branches consist of thick medullary 

hypothallus surrounded by well-developed marginal 

perithallus. Hypothallus, 700//-900// thick, composed 

of regularly alternate rows of long and short cells; long 

cells 41/4-56/x by 9/r-14/x, short cells 16/x-24/x by 9/r-14/x. 

Perithallus fairly regular layers of cells 10/r-15/x by 

9//-10//. Conceptacles not observed.

Remarks. This is another member of the small group 

of branching Lithophyllum characterized by having a 

medullary hypothallus with regularly alternate layers 

of long and short cells. To date only seven members 

of this group are known. Of these, four are Miocene, 

one Pleistocene and Recent, and two Recent. They 

are compared in the following table. L. alternatum is 

very close to the Recent L. moluccense. However, 

without a knowledge of the conceptacles it seems 

desirable to consider it as a separate species.

Occurrence: Upper Miocene, Alifan Limestone. Loos. Jl 2-2, 

Ts 16-3 (D939), and Ts 16-1(4) (D937).

Figured specimens: Holotype A733. Also figured: A734.

Comparison of measurements, in microns, of species of Lithophyllum having hypothallus with alternate layers of long and short cells

[From random sections]

Species

Lithophyllum 

bamleri Heydrich 1 .

moluccense Foslie

premoluccense Lemoine

alternatum Johnson n. sp

alternicellum Johnson n. sp

lemoini Raineri

Medullary hypothallus

Long cells

Length

27-60 

22-36 

34-58

50-85 

41-56 

32-41 

100-130

Width

7-15 

9-14 6-14

10-12 

9-14 

8-13 

10-13

Short cells

Length

12-30 

11-22 

14-28

15-30 

16-24 

22-25 

30-33

Width

16-20 

7-14 

6-14

10-12 

9-14 

8-13 

10-13

Perithallus

Length

6-120 

9-18 

10-20

15-130 

10-15 

9-16 

10-12

Width

8-10 

9-14 

6-12

10 

9-10 

9-14 

12-13

Conceptacles

Diameter

600-700 

240-400 

200-310

100-160 (2 ) 

208-224

(2 )

Age

Recent. 

Do. 

Recent and Pleistocene. 

Miocene. 

Do. 

Do. 

Do.

1 In L. bamleri there is an alternation of two layers of long cells with one layer of short cells; in all the others the alternation's one long with one short.

2 Not known.

lithophyllum alternicellum Johnson n. sp.

Plate 6, figures 3, 4

Description. Branches contain thick coaxial medullary hypothallus and moderately developed marginal 

perithallus. Hypothallus consists of regularly alternate 

layers of long and short cells; long cells 32//-41// by 

8/4-13/*, short cells 22/4-25/4 by 8/4-13/4. Perithallus 

9//-16// by 9/4-14^. Conceptacles 208//-224// in diameter and 66/4-71/4 high.

Remarks. This species belongs to the small group of 

Lithophyllum characterized by having the hypothallic 

tissue formed of alternate layers of long and short cells. 

The only other known Miocene species of this group 

is L. premoluccense Lemoine which, however, has much 

longer hypothallic cells and appreciably smaller conceptacles.

Occurrence: Lower Miocene, Bonya Limestone. Locs. Gj 7-2 

(D909) andlh 5-6 (D929).

Figured specimens: Holotype A735. Also figured: A736.
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM G21

lithophyllum aff. I. glangeaudi lemoine

Plate 6, figure 6

Lithophyllum glangeaudi Lemoine, 1939, Mat. Carte geol. de 

1'Algerie ser. 1, Paleont. no. 9, p. 102-103, pi. 2, fig. 15, 

text fig. 70; p. 107.

Description. Strongly branching form has a thick 

perithallic layer, cells with a considerable range in 

size, 9ju-26ju by 7^-11 p. Hypothallic tissue does not 

show a strongly defined layered structure; cells in 

rows 8ju-12ju wide with very poorly defined cross partitions. No conceptacles present.

Remarks. The character of the perithallic tissue, 

size of perithallic cells, and the branching habit suggest 

L. glangeaudi described by Lemoine from the middle 

Miocene of Algeria. However, without a better knowledge of the hypothallus and conceptacles only a 

resemblance can be suggested.

Occurrence: Upper Miocene, Alifan Limestone. Loc. Ts 9-1 

(D936).

Figured specimen: A737.

lithophyllum cf. L. kladosum Johnson

Lithophyllum kladosum Johnson, 1954a, U.S. Geol. Survey Prof. 

Paper 260-M, p. 539, pi. 192, figs. 1-8.

Description. Fragments of long, slender branches 

containing well-developed medullary hypothallus and 

marginal perithallus. Hypothallus formed of gently 

arched layers of cells 40/^-52^ by 13^-21^. Perithallic 

cells nearly square 13M-15/Z by 11^-15^. Conceptacles 

unknown.

Remarks. The Guam specimens closely resemble the 

material described as L. kladosum from the lower 

Miocene of Bikini. They are identical in cell measurements and growth habit but differ by having a thinner 

marginal perithallus.

Occurrence: Lower Miocene, Maemong Limestone Member 

of Umatac Formation. Loc. Ef 2-1.

lithophyllum kotschyanum (Unger) Foslie form madagascariensis Foslie

Plate 14, figures 1-2; plate 15, figure 3

Lithophyllum madagascarense Heydrich, 1902, Quelqu. Nouv.

Melob., p. 473. 

Lithophyllum kotschyanum (Unger) Foslie, 1909, K. norske

vidensk. selsk. Skr., no. 2, p. 34 . 

Foslie and Prints, 1929, K. norske vidensk. selsk. mus.

Mon., p. 35, pi. 65.

Description. Plant develops as flattened hemispherical or very flattened conical mass; closely packed 

branches as much as 6 inches in diameter and 3 inches 

in height form thick platy or leaflike masses. Plant

688376 O 63 3

grows firmly attached to hard object, commonly coral; 

some plants develop into flat shelflike or bracketlike 

masses; numerous conceptacles on upper surfaces of 

some specimens. Section through branch shows medullary hypothallus and marginal hypothallus that grade 

one into the other. Hypothallus wide, tissue quite 

regular, arched layers of rectangular cells 23^-37^ by 

10^-14^. Perithallus regular layers of cells 9/jL-lQfj. by 

6^-13^. Conceptacles numerous, diameters 300^-450^; 

tops flattened or slightly depressed with single short 

wide aperture.

Remarks. Lithophyllum kotschyanum is a highly 

variable species widely distributed in the Indian Ocean 

and the tropical Pacific. Foslie described five growth 

forms. The Guam specimens closely fit his form 

"madagascariensis" which was characterized by having 

wide platelike branches. They differ only in that the 

branches are wider than the type from Madagascar. 

In other words, they are more extreme than the type 

of the form. The cell dimensions and conceptacle 

sizes agree with the types both of the form and the 

species.

It is interesting to note that in the collections from 

Saipan studied by the author forms typica and subtilis 

were observed to be more extreme than Foslie's types of 

those forms, whereas at Guam the form madagascariensis 

is more extreme than the type. In comparing a suite 

of specimens, resemblances can be seen between form 

subtilis and form typica and between typica and madagascariensis, but the differences in appearance between 

subtilis and madagascariensis are so great that they 

would be considered entirely different species were it 

not for identical microstructure, cell dimensions, and 

shape and size of conceptacles.

The form is quite abundant on Guam, on the quiet 

inner side of the Agana Reef, where it grows at depths 

of 1-10 feet below low-tide levels.

Occurrence: Agana Reef (D946). 

Figured specimens: A738 and A739.

lithophyllum moluccense Foslie 

Plate 13, figures 1, 3

Lithophyllum moluccense Foslie, 1901, Kl. norske vidensk. selsk.

Skr., no. 6, p. 24. 

Weber van Bosse and Foslie, 1904, Siboga-Expediiie Mon.

61, p. 67, pi. 12. 

Foslie and Printz, 1929, Kl. norske vidensk. selsk. mus.

Mon., p. 36, pi. 50. 

Johnson, 1957, U.S. Geol. Survey Prof. Paper 280-E, p. 230,

pi. 58, figs. 2-5.

Description. Plant strongly branching, bushy, commonly compact hemispherical or spherical masses, some 

small tufts; average diameter 3-4 inches, maximum 6-7 

inches; large plants are wide and flat.
G22 GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

Normally plants- start growing attached to hard 

object such as coral, later may become detached and 

grow loose on bottom; broken branches may develop 

new plants. At a few localities around Guam nearly 

spherical masses were growing loose on bottom, especially abundant on inside of Cocos Island reef of Merizo 

Bay at depths of 6-15 feet.

Three varieties or growth forms recognized around 

Guam. Foslie named these typiea, flabelliformis, and 

pygmaea; form typiea develops relatively long strong 

thick branches rather widely spaced (Johnson, 1957, 

pi. 58, figs. 2-4); form Jlabelliformis has tightly packed 

short, stubby, flattened branches (pi. 13, fig. 3); form 

pygmaea has short slender tightly packed branches 

(pi. 13, fig. 1). In both typiea and pygmaea branches 

tend to bifurcate at wide angle (75°-100°) and have 

gently rounded or blunt ends. Typical specimens of 

the three forms are quite distinct and differ appreciably in general appearance. However, in a large collection specimens can be found intermediate between 

the types. In the Guam collections typiea &n.d flabelliformis are common; pygmaea is much less abundant.

Branches contain well-developed medullary hypothallus and marginal perithallus. Hypothallus forms 

50-60 percent of branch diameter; alternate layers of 

long and short cells rectangular in section; short cells 

14ju-28/4 by 6/4-14ju; long cells 34/4-58/4 by 6^-15^. 

Lengths are measured at center of row; cells become 

shorter toward margins.

Marginal perithallus commonly 0.350-0.400 mm 

thick; smaller cells 10/4-20/4 by 6ju-12ju (average 18/4 

by 10/4). In section, cells of inner layers oblong, cells 

of outer layers square. Conceptacle chambers 0.200- 

0.310 mm in diameter (average 0.250-0.275 mm). 

Roof pierced by single large pore.

Remarks. This species is common at all localities 

from which collections of Recent algae were made and 

is the most abundantly represented species in the Guam 

collections.

Occurrence: All reefs where collections of Recent algae were 

made; also Pliocene and Pleistocene, Mariana Limestone. Loc. 

GMH-1, depth 30-35 ft; Agana Reef (D946) and Cocos Island 

Reef (D903).

Figured specimens: A740, A741, and A782.

Lithophyllum pseudoamphiroa Johnson n. sp. 

Plate 7, figures 1-4

Description. Thallus starts with basal crust from 

which develop long, slender branches, may branch repeatedly. Basal hypothallus coaxial, 250/4-300/4 thick, 

cells 39;u-57;u by 14ju-19/4. Branches consist of medullary hypothallus of gently arched layers, large rectangular cells 36/^-63/4 by 13/4-21/4 (average about 53/x 

by 20/4). Suggestions of single .outer dermal layer of

Locality

Fi6-5.... . -

Fj 2-4.... ... ... ... 

Fj 2-4.. ....................

QjS-1. .....................

Ii6-2Q.. ........ ....... .....

Basal hypothallus 

cells

Length

39-57

Width

14-19

Medullary hypothallus cells

Length

36-59 

56-63 

50-55 

41-53 

52-62

Width

13-22 

17-22 

14-19 

17-25 

13-19

Thickness 

of 

branches

933 

800-988 

875-910 

765-1, 101 

1,016

smaller cells. Most branches had diameters of 

l,000ju. No conceptacles observed.

Detailed dimensions, in microns, of three typical specimens of 

Lithophyllum pseudoamphiroa Johnson n. sp.

[From random sections]

Remarks. Superficially, fragments of branches of 

this species strongly suggest segments of a long, slender 

Amphiroa. However, the lack of articulation (alternation of long calcified segments with short uncalcified 

nodes) and the well-developed coaxial basal hypothallus 

place it in the genus Lithophyllum. The cells are longer 

than most species of Lithophyllum but are shorter than 

those of most Amphiroa.

A number of pieces of this species were observed in 

the Miocene collections from Saipan but were too 

fragmentary or too poorly preserved to permit an adequate description.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Locs. Fi 6-5, Fj 2-4 (D900), Gj 3-1, li 6- 

25 (D919), and li 6-26.

Figured specimens: Holotype A697 (the slide contains two 

specimens figured). Also figured: A743.

Lithophyllum traceyi Johnson n. sp. 

Plate 6, figures 1, 2

Description. Strongly branching form; branch 

lengths more than a centimeter, widths 450ju-1200ju. 

Wide medullary hypothallus, 300ju-l 100/4 thick; moderately developed marginal perithallus. Hypothallus 

coaxial of gently arched layers of cells; most specimens 

show distinct growth zones; considerable range in size 

both in same layers and between adjoining layers of 

cells, 12/4-30ju by 7ju-15/4. Perithallus regular layers 

of cells 10/4-1 SM by 8/4-13/4. Conceptacle chambers 

221ju-288/4 in diameter, 149ju-168/4 in height.

Remarks. This species belongs in the same general 

group as L. oblongum, L. kladosum, and L. profundum, 

described by Johnson (1954a) from the Miocene of 

Bikini. It differs from them, however, by having 

shorter cells.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Locs. Fi 6-7 (D899), Fj 2-1, Gi 1-3, Hi 

3-6, Hi 10-1, li 6-31, li 6-34 (D925), and li 6-38.

Figured specimens: [Holotype] A698. Also figured: A745.
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM G23

hetailed measurements, in microns, of Lithophyllum traceyi Johnson n. 

[From random sections]

Locality

Fi6-7-__ _-__ -.__-_

Fj 2-1. _____________________

Gil-3__________, ___________

Hi 3-6__ ____________________

Hi 10-1- __________-

li 6-31_._. __________________

li 6-34___. ___-_--_____-_____

li 6-34.__. __________________

li 6-38 ___________________

Hypothallus cells

Length

9-30 

17-28 

24-31 

20-27 

19-26 

22-26 

14-25 

23-29 

21-26

Width

8-12 

12-15 

12-15 

10-13 

7-10 

11-13 

9-11 

8-10 

10-11

Perithallus cells

Length

10-14 

13-16 

9-12 

10-16 7-15

11-14 

14-18 

14-17

Width

9-11 

8-11 

9-13 

10-13 

9-10

6-12 

8-10 

6-9

Conceptacles

Diameter

220

221-288

Height

149-168

Thickness

Hypothallus

550-700 

1, 066-1, 256 

304-415 

791-823 

579-614 

256-305 

600 ± 

775-787 

878-926

Perithallus

180-250 

333-488 

115-360 

160-195 

186-278 

80-120 

100-150 

282-298 

505-593

lithophyllum sp. C 

Plate 6, figure 5; plate 7, figure 5

Description. Long, slender branches, well-developed 

medullary hypothallus and marginal perithallus. Hypothallus has strongly arched layers of cells with thick 

walls between layers; cells 18^-24^ by 10^-14^- 

Perithallus has slightly wavy layers of cells, also 

separated by thick walls; strong suggestion of alternation of layers of longer cells with layers of slightly 

shorter cells; cells 16^-19^ by 7^-11^- Conceptacle 

chamber with a diameter of 275^ present on the slide, 

but conceptacle probably not cut through center.

Remarks. Represented by a single tangential section (pi. 6, fig. 5) and an oblique section which does not 

show the true relative widths of hypothallus and 

perithallus. This form suggests L. premoluccense 

Lemoine but has much shorter cells.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Loc. li 6-37 (D927). 

Figured specimens: A710a, and A710b.

lithophyllum sp. F

Plate 12, figure 7

Description. Strongly branching form, unusually 

regular tissue. Medullary hypothallus thickness 394^u410M, regular layers of cells suggest growth zones; cells 

17M-27M by QM-HM- Marginal perithallus 98M-187M 

thick, well-defined layers of cells 9^-16^ by 6M-9MConceptacles unknown.

Remarks. The cell dimensions and regularity of the 

tissue separate this from any known Miocene or Pliocene 

species, but with only one good specimen available for 

study and without a knowledge of the Conceptacles, it 

does not seem wise to give it a specific name.

Occurrence: Upper Miocene, Alifan Limestone. Loc. Hn 7-2 

(D916).

Figured specimen: A748.

Genus POROLITHON Foslie, 1909

Porolithon resembles Lithophyllum in having, normally, a coaxial hypothallus, a perithallus composed of

layers of cells, and Conceptacles of sporangia each 

possessing a single large aperture in the roof for the 

escape of spores. It differs from Lithophyllum primarily by having in the perithallic tissue lenses of megacells 

parallel to the layers of cells. The horizontal grouping 

of the megacells distinguishes Porolithon from Goniolithon, in which megacells occur singly or in short 

vertical rows perpendicular to the cell layers. As a 

result of the presence of the megacells, the perithallic 

tissue is not as regular as is commonly the case with 

Lithophyllum. Another distinctive feature of Porolithon 

is the common presence of lateral pores connecting 

adjoining cells.

The genus contains both encrusting and branching 

forms. It is known from the Pleistocene and Recent 

and is represented today in the tropical Pacific by a few 

widely distributed species.

Several Recent species were observed on the reefs at 

Guam, and one Pleistocene species was studied.

Porolithon onkodes (Heydrich) Foslie

Lithothamnion onkodes Heydrich, 1897a, Deutsche bot. Gesell. 

Ber., v. 15, p. 410.

Heydrich, 1897b, Bibliotheca Botanica, v. 41, p. 6, fig. 11. 

Weber van Bosse and Foslie, 1904, Si&o0a-Expeditie Mon.

61, p. 57, pi. 11. 

Foslie and Printz, 1929, K. norske vidensk. selsk. mus.

mon., p. 33, pi. 67, figs. 1-8. 

Porolithon onkodes (Heydrich) Foslie. Taylor, 1950, Michigan

Univ. Studies, Sci. Ser., v. 18, p. 125, pis. 9, 61-63. 

Johnson, 1954a, U.S. Geol. Survey Prof. Paper 260-M, p.

537, 542, pi. 194, figs. 1-4; pi. 195, fig. 4. 

Johnson, 1957, U.S. Geol. Survey Prof. Paper 280-E

p. 232-233, pi. 55, figs. 6, 7; pi. 59, fig. 6.

Description. Plants encrusting; individual crusts 

thin but superimposed thalli may develop as thick 

crust or nodular mass. Surface smooth to rough with 

dull or semidull luster. Thin crusts conform to irregularities of substratum; thick crusts flat or gently 

rounded. Hypothallus thin, ranging from few rows of 

cells up to 30(V thick; cells rounded to rectangular, 

elongated, 12^-21^ by 7^-12^. Most of crust is perithallic tissue, well-defined layers of rectangular cells,
G24 GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

by 6/1-7^. Abundant megacells occur in 

lenticular clusters. Conceptacles numerous, flattened 

tops, diameters of 175^-300^.

Remarks. The Guam material agrees with Foslie's 

description and is similar to that from Saipan. The 

conceptacles are slightly larger than those described 

by Taylor from Bikini but are within the range given 

by Foslie.

Occurrence: Found at all localities where Recent collections 

were made.

Porolithon craspedium (Foslie) Foslie

Lithophyllum craspedium Foslie, 1900b, K. norske vidensk. selsk.

Skr., no. 5, p. 26, 27. 

Lithophyllum (Porolithon) craspedium Foslie. Foslie, 1909, K.

norske vidensk. selsk. Skr., no. 2, p. 43, 44. 

Lithophyllum craspedium Foslie. Foslie and Printz, 1929, K.

norske vidensk. selsk. mus. Mon., p. 33, pi. 69, figs. 1-7. 

Porolithon craspedium (Foslie) Foslie. Taylor, 1950, Michigan

Univ. Studies, Sci. Ser., v. 18, p. 126-128, pis. 64, 65. 

Johnson, 1954a, U.S. Geol. Survey Prof. Paper 260-M, p.

541, pi. 193, figs. 1-5; pi. 194, fig. 5. 

Johnson, 1957, U.S. Geol. Survey Prof. Paper 280-E, p. 232,

pi. 56; figs. 4-5; pi. 59, figs. 1-3.

Description. Variety of growth forms, commonly 

cushion-shaped subconical or flattened cylindrical. 

Branches coarse, fingerlike, wedge shaped, or forming 

rounded protuberances. Grows very firmly attached 

to hard firm mass, commonly coral or other crustose 

corallines; very solid and massive. Surface slightly 

rough, semilustrous. Living plants commonly have 

gray tinge. Conceptacles small, not prominent. Tissue 

not noticeably differentiated into medullary hypothallus 

and perithallus, dense, not very regular layers of rectangular cells 8fj,-15n by 7//-11M- Lenses of megacells 

rather regularly spaced throughout tissue. Megacells 

irregular, rounded, 15^-34 (40) n long and 7n~l5n in 

diameter, 6-12 in a row in sections. Conceptacles 

abundant, small, flattened tops, 200^-285/z in diameter.

Remarks. In appearance, structure, and cell dimensions, the Guam material resembles Foslie's descriptions. The conceptacle size averages a little larger 

than Foslie's specimens from the South Pacific and 

Indian Ocean.

Occurrence: Pleistocene, Mariana Limestone. Recent reefs. 

Genus GONIOLITHON Foslie, 1900

In appearance, growth habit, and general structure 

Goniolithon closely resembles Lithophyllum. It has 

similar single-apertured conceptacles and commonly, 

though not always, has a coaxial hypothallus. The 

generic distinctions stressed by Foslie deal entirely 

with minute structural features of the sporangia and 

their position within the conceptacles, features seldom 

seen in fossils. The most distinctive structural feature 

seen in thin sections is a development of megacells in 

the perithallic tissue. These megacells are long and 

have diameters two or three times as large as the 

ordinary cells. They may occur singly or in short rows 

perpendicular to the layers of the tissue.

From the present study the author would also add 

the following features: All the Recent specimens of the 

genus from Guam have a dull luster on the surface of 

dried specimens which is quite a contrast to the shiny 

luster of most Lithophyllum. Also in Goniolithon the 

development of secondary hypothallic scar tissue over 

injuries, foreign objects, and conceptacles seems to occur 

much more commonly than in other genera.

The first recorded fossil occurrence of Goniolithon is 

from the early Miocene; it developed steadily during 

the Pliocene and is common in Pleistocene beds and 

in Recent tropical seas where it is represented by 

numerous individuals of a few widely distributed species. 

It develops both crustose and branching forms.

The dimensions and distribution of the species found 

on Guam are given in table 10.

TABLE 10. Measurements in microms, and distribution of species of Goniolithon (from Guam}

Species

Goniolithon cf. O. fosliei (Heydrich) 

Foslie. 

frutescens Foslie.. _ _ ...

miocenicum Johnson n, sp_

reinboldi W.v Bosse and Foslie

sp. C_. ........

Hypothallus cells

Length

29-41 

17-34

22-27 

12-26

22-33

Width

11-18 

11-23

13-22 

6-14

9-15

Perithallus cells

Length

28-41 

12-25

9-21 5-18

16-33 

10-18

Width

11-18 

9-16

8-18 4-14

16-20 9-13

Megacells

Height

20-40 

25-45

25-68 

13-30

30-42 

11-18

Width

18-33 

18-29

22-32 

9-21

26-30 

18-28

Conceptacles

Diameter

750-1, 250 

350-425

480-670 

69-87

25(MOO

Height

200-325

300-475 

58-77

150-230

Localities

Fdl-1, Fd4-l, Fi3-4, FJ2-4, 

Gl-1, G14-2, Hi 10-1, 116-31, 

li 6-34. 

All reefs _ --..- __ . ..

Ts 9-1..... _-_------..--------.

Age

Recent.

Recent and 

Pleistocene. 

Recent. 

Miocene.

Recent. 

Miocene.
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM G25

Goniolithon cf. G. fosliei (Heydrich) Foslie 

Plate 13, figure 2

Lithothamnion fosliei Heydrich, 1897a, Deutsche bot. Gesell.

Ber., v. 15, p. 58. 

Goniolithon fosliei (Heydrich) Foslie. Weber van Bosse and

Foslie, 1904, £i'6ogra-Expeditie Mon. 61, p. 46, pi. 9,

figs. 1-5.

Description. Thin rather even crust on corals and 

other coralline algae. In section well-developed moderately coaxial hypothallus 0.250-0.400 mm thick and 

much thicker perithallus. Hypothallic cells long, 

rectangular, or wedge shaped, 29ju-41ju by llju-lSjuPerithallic rectangular cells with rounded corners and 

abundant short vertical clusters of megacells; considerable range in size, 28ju-41ju by llju-18ju. Barrel- or 

cushion-shaped megacells, generally in vertical groups 

of three to five; size range 20jit-40ju in length and 

18ju-33ju in diameter. Conceptacles large, wide, and 

flat, long nipples leading to aperture; chambers 750;ul,250ju in diameter and 200;u-325ju in height.

Remarks. In appearance, growth habit, and general 

structure this species resembles Foslie's descriptions 

and illustrations of specimens from the Indian Ocean 

and East Indies. However, the Guam material has 

appreciably larger cells, smaller Conceptacles, and less 

perfectly developed coaxial hypothallus. Possibly it 

is a new species. This may be decided by later more 

extensive collections.

Occurrence: Recent, Agana Reef (D946). 

Figured specimen: A749.

Goniolithon frutescens Foslie

Goniolithon (Cladolithon) frutescens Foslie, 1900a, K. norske

vidensk. selsk. Skr., no. 1, p. 9-10.

Goniolithon frutescens Foslie. Foslie, 1900c, The fauna and 

geography of the Maldive and Laccadive Archipelagoes, 

p. 468, pi. 25, figs. 5-6. 

Weber van Bosse and Foslie, 1904, Si&ogra-Expeditie Mon.

61, p. 53, pi. 10, figs. 10-11. 

Foslie and Prinz, 1929, K. norske vidensk. selsk. mus. Mon.,

p. 30, pi. 48.

Johnson, 1957, U.S. Geol. Survey Prof. Paper 280-E, p. 231 

pi. 59, fig. 4; pi. 60, fig. 3.

Description. Bushy tufts or loose rounded masses; 

branches long delicate irregular, fused at base but 

separated for most of length, commonly 3.5 cm long 

and as thick as 3 mm, surface dull, nearly smooth, or 

somewhat irregular. Plant starts attached to hard 

object such as a coral, pebble, or another alga. Later, 

plant may become detached and grow loose on bottom. 

Plants fragile, branches separating and breaking easily. 

Branches distinct, medullary hypothallus generally 

composes 50-70 percent of diameter and marginal perithallus ; few specimens very thin epithallus. Medullary 

hypothallus gently curving layers of rectangular cells

nearly flat at center; layers quite uniform in size and 

arrangement; cells 17ju-34ju by llju-23ju, walls fairly 

thick; patches of secondary hypothallic scar tissue 

noted on many specimens. Perithallus rather irregular, 0.300-0.400 mm thick; irregular layers of cells 

varying considerably in size 12;u-25ju long by 9ju-16ju 

wide. Megacells irregularly distributed throughout 

perithallic tissue especially near margins, rounded or 

barrel-shaped, appearing singly or in rows of 2, 3, or 

4 perpendicular to cell layers; cells 25ju~45ju long by 

18ju-29ju in diameter. Several slides showed presence 

of thin epithallus, single layer of flattened cells about 

lOju high. Conceptacles rare; 350ju-425ju in diameter. 

Remarks. In appearance and cell dimensions the 

Guam material agrees with Foslie's description of the 

species from Funafuti, the East Indies, and the Indian 

Ocean. It differs by developing larger more luxuriant 

plants, with longer branches. Megacells occur more 

abundantly in the Guam specimens than in Foslie's 

type from Funafuti. All the Guam species belong to 

Foslie's form typica.

Occurrence: Pleistocene, Mariana, and Recent. The species is 

relatively common in shallow backreef areas around Guam where 

it is found associated with corals.

Goniolithon medioramus Johnson n. sp.

Plate 13, figures 4, 7; plate 15, figures 1, 2

Diagnosis. Thallus compactus vel nodulosus ramorum 

brevium condensatorumque; rami 3-5 mm ad basim 

crassi, 1-1.5 cm longi, hypoihallo medullari et penthallo 

marginali amplis; tela hypothalli regularis, cellulis 

22ju-27ju longis, 13ju-22ju latisque; perithallus irregularis, 

cellulis 9ju-21ju longis, 8ju-18ju latisque; megacellulae 

25ju-68ju altae, 22;u-32ju lateaque; conceptacula 350ju-475ju 

alta, 570ju-670ju lataque, foraminibus longis.

Description. Plants form bushy to nodular masses 

of short branches averaging 3-5 mm _thick at base, 

tapering toward ends; branches tightly packed, commonly bifurcated, ends rounded, as much as 2.5 cm 

long with average length 1-1.5 cm. Plants start growing around hard object, commonly end of coral branch 

or loose piece of coral. Nodular masses attain lengths 

of 3-8 cm. Sections of branches show well-developed 

medullary hypothallus and thin irregular basal hypothallus of arched layers of rectangular cells, regularly 

arranged; cells 22^-27ju long by 13^-22^ wide. Perithallus irregular, composed of irregular rows of rectangular to rounded cells varying considerably in size, 

9ju-21ju long by 8ju-18/i in diameter. Megacells numerous in perithallic tissue, 25ju-68ju long by 22ju-32ju 

wide. Conceptacles terminal in medullary tissue; 

ratio of height to diameter large; they have unusually 

long nipplelike apertures. Measurements (in microns) 

of conceptacle chambers follow.
G26 GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

Diameter

625.

570.

Height 

400 

350 

300 

340

450

Diameter Height 

350 

350 

330 

450 

2 475

1 Aperture of nipple 230j_ long.

2 Aperture of nipple 260j_ long.

Remarks. -This species is close to G. breviclavium 

described by Foslie from Hawaii but has larger cells 

and longer and more tightly packed branches and 

slightly smaller conceptacles.

It is intermediate between G. laccadivicum and G. 

frutescens in most features (cell dimensions, size of conceptacles, and character of branches). G. frutescens 

has long, relatively slender branches and G. laccadivicum 

has short round warty branches, whereas G. medioramus 

has medium-length branches, thick at the base but 

tapering toward the tips. The conceptacles of G.

medioramus resemble those of G. laccadivicum but are 

smaller. They differ both in shape and size from those 

of G. frutescens.

Occurrence: Recent. This species is fairly common on the 

Agana Reef and the reefs along the southwest side of the island. 

Agana Reef (D946).

Figured specimen: Holotype A752. Also figured: A750 and 

A751.

Goniolithon miocenicum Johnson n. sp.

Plate 8, figures 1-3

Description. Thallus is an irregular crust with 

moderately developed hypothallus and considerably 

thicker perithallus. Hypothallus coaxial 109/.-484/. 

thick, cells 12/.-26/. by 6/.-14/U. Perithallus 176/U-836/. 

thick, tissue fairly regular, layers of cells 5/.-18/. by 4/_- 

14/jL. Megacells sized 13/.-30/. by 9/_-21/u fairly abundant; normally single (rather than in vertical groups) 

and fairly regularly spaced in cell layers. Conceptacles 

small 69/,-87/u in diameter and 58//-77/Z high.

Detailed measurements, in microns, of Goniolithon miocenicum Johnson n. sp. 

[From random sections. Cleared entries indicate absence of conceptacles]

Locality

Fdl-l_____________________

Fd 1-1. ____________________

Fd 1-1. ____________________

Fd4-l_____________________

Fi3-4_. ____________________

Fj 2-4_-__-______-____-_____

Fj 2-4____-_----_-_-__-_--__

Gi 1-1

Gi4-2__-__-_-_-__-__-__-___

Hi 10-1____________________

Ti6-31._. _-___---__________

li 6-34

Range _

Hypothallus cells

Length

13-120 

17-26

20-26 

19-26

17-26 

17-26

16-22

12-21 

20-24

12-27

Width

6-9 

9-14

7-12 

9-12

10-13 

7-11

7-19 

8-13 

9-11 

6-14

Perithallus cells

Length

b-ll 

6-13 

9-18 

7-11 

9-13 

8-13 

6-11 

9-14 

7-11 

8-11 

10-18 

5-9 

5-18

Width

4-8 

8-12 

8-12 

6-11 

7-11 

8-11 

6-10 

8-14 

5-10 

5-7 

8-10 

6-9 

4-14

Megacells

Length

14-18 

18-25 

18-22 

16-22 

21-30 

18-25 

13-18 

18-26 

15-26 

9-13 

14-28 

8-14 

13-30

Width

12-18 

13-18 

17-18 

11-16 

13-18 

11-15 

11-12 

15-21 

11-17 

9-11 

11-16 

11-14 

9-21

Conceptacles

Diameter

69-87 

69-87

Height

58-77

Thickness

Hypothallus

81-104 

136-115 

109-118 

171 

154-176

340 

132-176

484 

160+ 

117-130 

109-484

Perithallus

484-704 

583-704 

220 

211 

352-492 

484 

290 

836

308 

792 + 

176-184 

176-836

Remarks. This is the first unquestionable species of 

Goniolithon the writer has observed in beds of Miocene 

age. The structure is similar to that of Recent members of the genus except that the megacells occur singly 

rather than in vertical groups or columns and they are 

more regularly spaced. The species occurs abundantly 

in the Maemong Limestone Member.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Locs. Fd 1-1 (D894), Fd 4-1, Fj 2-4 

Gi 1-1 (D904), Hi 10-1, li 6-31, and li 6-34. Lower Miocene, 

Bonya Limestone. Locs. Fi 3-4 (D896) and Gi 4-2.

Figured specimens: Holotype A753. Also figured: A755 and 

A754.

Goniolithon reinboldi Weber van Bosse and Foslie

Plate 13, figures 5-6; plate 15, figure 4, 5 

Goniolithon reinboldi Weber van Bosse and Foslie. Foslie, 1901,

K. norske vidensk. selsk. Skr., no. 6, p. 5. 

Weber van Bosse and Foslie, 1904, $&&ogro-Expeditie Mon.

61, p. 49, fig. 21; pi. 10.

Johnson, 1957, U.S. Geol. Survey Prof. Paper 280-E, p. 231, 

pi. 59, fig. 5.

Description. The plant commences as a thin crust 

on coral, crustose coralline algae, or some other hard 

object; later warty excrescences develop which may be 

widely or closely packed; the surface often is covered 

by tiny pimplelike conceptacles as the plant seems to 

fruit at all seasons. Perithallic structure is unusual, 

hence characteristic. Perpendicular section shows thin 

hypothallus with 1-6 layers of greatly elongated nearly 

rectangular cells. Perithallus forms most of the tissue, 

thin but irregular layers of irregularly arranged rounded 

cells having quite a size range (15/.-33/. long by 15/.-30/. 

in diameter). Streaks of secondary hypothallic scar 

tissue may occur over conceptacles, injured areas, or 

bits of foreign material. Megacells are not abundant 

and, because of irregular tissue, not conspicuous as in 

G. frutescens or G. medioramus; megacells occur irregularly throughout tissue, 30/.-42/. long by 26/.-30/. 

wide. Conceptacles are very abundant, circular in
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM G27

plan, and highly arched in vertical section; commonly 

250AI-400M in diameter and 150/r-230/* high.

Remarks. This species is common and easily recognized in section. Superficially it resembles Liihophyllum okamurai Foslie with which it is frequently 

associated.

The Guam material agrees with Foslie's description 

and illustrations of specimens from the East Indies 

and the Indian Ocean except that it commonly has a 

slightly thicker hypothallus.

Occurrence: Recent. Found at all the Guam reef localities. 

Agana Reef D946.

Figured specimens: A756, A757, A758, and A759.

Goniolithon sp. C

Plate 8, figure 4

Description. Represented by single fragment of 

thick irregular crust, mainly perithallic tissue but showing several patches of hypothallic scar tissue with 

coaxial hypothallus up to about 200^ thick and cells 

22/r-33/j by 9/j-15/j. Perithallus has moderately regular 

layers of cells lO/i-18/* by 9/r-13/*. Megacells in short 

vertical rows or columns commonly containing 4 or 5 

cells; wide flattened rounded or rectangular cells 11/rISfj, high by 18^-28^ wide; columns fairly regularly 

spaced through certain zones of perithallus. Conceptacles unknown.

Remarks. This form shows structural details similar 

to those of Kecent species. It is a very interesting find. 

However, with only a single fragment to study and 

without a knowledge of the conceptacles it does not seem 

desirable to give it a specific name.

Occurrence: Upper Miocene, Alifan Limestone. Loc. Ts 9-1 

(D936). 

Figured specimen: A715.

Genus AETHESOLITHON Johnson, n. gen. 

(Aethes strange, unusual; lithon stone)

Description. Plants crustose, branching. Tissue 

irregular, with irregular layers or lenses of cells. Cells 

rounded to polygonal, frequently large. Branching 

forms show well-developed medullary hypothallus of 

large polygonal cells and marginal perithallus of irregular layers of rounded to polygonal cells. Conceptacles 

small and highly arched. Detailed measurements are 

given in table 11.

Remarks. This genus is very different from any 

Cenozoic coralline algae known to the writer. Large 

polygonal cells are common in Paleozoic algae but are 

seldom found in Cenozoic ones. Only one other Cenozoic genus of coralline algae has large polygonal cells, 

Subterraniphyllum Eliott, 1957, which is a member of 

the articulate coralline algae (Corallinoideae), not the 

crustose coralline algae (Melobesioideae), and has an 

entirely different tissue structure.

Maslov's (1956, p. 107) genus Mesolithon Maslov, 

1955, from the Late Cretaceous also has polygonal cells. 

This genus is characterized by having the tissue differentiated into three zones: the hypothallus, mesothallus, and perithallus. The mesothallus contains polygonal cells of varying size, showing a lack of any orderly 

arrangement. This is quite distinctive but very different from the tissue of Aethesolithon, in which the cells 

are arranged in definite layers of rows in the individual 

lenticular growth zones of the crustose forms and in 

very regular layers in the branches.

Two species have been recognized in the Guam collections, one from the lower Miocene and one from the 

upper Miocene.

Occurrence: Lower Miocene, Bonya Limestone; and upper 

Miocene, Alifan Limestone.

Type species: Aethesolithon problematicum Johnson, n. sp.

TABLE 11. Detailed measurements, in microns, of species of 

Aethesolithon from Guam

[From random section]

Locality

Hypothallus 

cells

Length Width

Perithallus 

cells

Length Width

Conceptacles

Diameter

Height

Growth form

Aethesolithon problematicum

Fi 3-2(1)...

F13-4 ...

F13-4 .

Fi 3-4(3)...

F15-1 ...

Gi 4-1 ..

Ih 5-6......

Jj 3-1(2)....

JJ5-1......

52-73

41-89

45-74

32-60

19-37

32-40

24-36

15-33

16-32

17-34

18-45

17-48

(')

17-48

19-27

17-58

16-23

16-25

18^32

15-31

10-32

14-20

140-180

170-180

100-113

Do.

Do.

Do.

Do.

crust.

crust.

Aethesolithon grandis

Eh 3-3.....

Ts 16-1

TS16-1.--.

Tsl6-4.--.

Tsl6-5.-__

26-110

215-23

27-130

26-57

212-26

54-77

11-26

39-43

25-65

22-68

19-27

25-41

9-27

21-29

20-32

22-31

13-18

23-37

230

175-225

175-250

210-240

145-155

125-150

125-175

Mammillated

crust.

Thin crust.

Branch.

1 Perithallus cells worn off.

2 Single layer of cells.

Aethesolithon problematicum Johnson n. sp.

Plate 9, figures 1-3

Description. Plant starts as irregular crust with 

warty protuberances or small mammillae, then develops 

definite branches.

Crusts appear to start with single layer of horizontally 

elongated and slightly oblique basal cells; unfortunately 

the few specimens showing this were so recrystallized 

that details are not clear and cell measurements 

uncertain. Rest of crust formed of very irregular 

layers or lenticular masses of polygonal cells with great 

range in size, 10/^-70^ in height by 8^-40^ in diameter. 

Commonly, these lenses or irregular zones are about
G28 GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

100/4 thick and composed of three layers of cells. In 

general, lower layer of large cells, next layer of cells 

somewhat smaller, and layer above still smaller.

Branches attain lengths of more than 6 mm with 

diameters of 2.5-3.0 mm; show well-defined medullary 

hypothaUus and marginal perithallus. Thickness of 

medullary hypothallus 1,200/4-1,300/4; strongly arched 

layers arranged in definite growth zones which in some 

specimens appear almost like thick lenses, each zone 

3-5 (commonly 4) layers of large polygonal cells. In 

long section cells appear as vertically elongated hexagons; cells alternate in position in successive rows so 

that the point of one cell fits between the points of 

those above and below (pi. 9, fig. 4). Lowest layer 

contains largest cells, uppermost the smallest; thus, in 

one lens length of cells in four rows measured as follows: 

lowest layer 89/4-95/4, second layer 80/4-85/4, third layer 

45/4-57/4, fourth and top layer 41/4-45/4 with widths 

30/4-42/4. In another lens (with five layers) maximum 

lengths were 68/4, 53/4, 40/4, 39/4, and 36/4. In another 

specimen, three-layered zone showed lengths of 82/4, 

65/4, and 50/4. In a given layer, cells also decrease in 

size from center to margins.

Marginal perithallus of branches formed of very 

irregular layers, commonly 2 or 3 layers to a growth 

zone. Cells rounded to polygonal, 20/4-35/4 high, rarely 

as much as 50/4 high. Conceptacles develop in outer 

layers of crusts and in perithallic tissue of branches, 

small and highly arched, 140/4-200/4 in diameter and 

100/4-140/4 high. Several specimens showed traces of 

enclosed sporangia. No specimen was observed which 

clearly showed aperture in roof for escape of spores, but 

small size and highly arched roof suggests probability 

of single opening.

Remarks. This species is common in the Bonya 

Limestone. The form described as Lithothamnium 

Tieteroihallum by Johnson and Ferris from the Miocene 

of Lau, Fiji, should be included in this genus and quite 

probably to this species.

Occurrence: Lower Miocene, Bonya Limestone. Locs. Fi 3-2 

(D895), Fi 3-4 (D896), Fi 5-1 (D898), Gi 4-1, Jj 3-1, Jj 5-1, and 

Ih 5-6.

Figured specimens: Holotype A754. Also figured: A762, and 

A763.

Aethesolithon grandis Johnson n. sp. 

Plate 9, figures 4, 5; plate 10, figures 7, 8

Description. Plant forms irregular crust that may 

become mammillated or develop branches. In crusts 

and mammillae tissue is irregular, containing lenticular 

growth zones with 3-5 layers of rounded or polygonal 

cells 21/4-70/4 by 21/4-29/4. Branches have well-developed medullary hypothallus surrounded by marginal 

perithallus. Hypothallus diameters as great as 3 mm; 

pronounced growth zones containing 6-8 (commonly 8)

layers of large polygonal cells, as large as 27/4-130/4 high 

by 21/4-77/4 wide in center of layers, commonly largest 

cells are in center of second or third layer from bottom 

of zone and become smaller toward top and margins. 

Perithallus moderately regular zones, each containing 

2-4 layers of rounded to polygonal cells 17/4-27/4 by 

9/4-29/4 wide.

Conceptacles develop in outer layers of the crusts, 

mammillae, and branches; relatively small and highly 

arched, 175/4-250/4 in diameter and 125/4-175/4 high.

Remarks. A. grandis resembles A. problematicum 

in general appearance and growth habit. It differs by 

having larger cells, longer and thicker branches, and 

larger Conceptacles.

Occurrence: Upper Miocene, Alifan Limestone. Locs. Eh 3-3 

(D892), Ts 16-1 (D937), Ts 16-4, and Ts 16-5 (D940).

Figured specimens: Holotype A764. Also figured: A767, 

A765, and A766.

Genus LITHOPORELLA Foslie, 1909

The genus Lithoporella is characterized by having 

thalli that form very thin crusts generally less than 

100/4 thick which grow attached to other calcareous 

algae, corals, Foraminifera, bryozoa, or other organisms. On some specimens numerous thalli grow superimposed and form thick crusts or nodular masses. 

Also, similar masses have been observed that were 

formed by interstratified thalli of Lithoporella with 

incrusting Foraminifera or, rarely, bryozoa. The 

Conceptacles are similar to those of Lithophyllum.

Each thallus of Lithoporella is formed by a single 

layer of long cells, except around the Conceptacles 

where they thicken and several layers of smaller cells 

may be present. The cells are elongated vertically and 

commonly slightly oblique. Most fossil specimens observed in thin sections are infertile; hence, the only 

feature available for use in classification is the size of 

the cells. Unfortunately, there is commonly a great 

range in cell length even in a single specimen. When 

Conceptacles are present, these also show a considerable range in size. This can readily be seen in the 

resume of the characteristics of the principal Recent 

species listed as follows.

Lithoporella melobesioides Foslie, cells 25^-85^ by 15^-30^.

Conceptacles 600^-1, 000^. 

atlantica Foslie, cells 32^-60^ by 18^-40^- Conceptacles

500^-800^. 

conjuncta Foslie, cells 36/i-55^ by 14^-30^- Conceptacles

It will be noted that each of these species shows great 

variation and they overlap one another so much that 

they could easily be considered as representing one 

quite variable species.

The same is true in most of the observed fossil species. 

Most fossil Lithoporella, in appearance and in dimen-
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM G29

sions of cells and conceptacles, easily fall within the 

range of Lithoporella melobesioides Foslie. Therefore, 

it seems only logical to attribute them to that one 

highly variable species which has a time range extending from the Eocene to Recent.

Lithoporella melobesioides (Foslie) Foslie

Mastophora (Lithoporella) melobesioides Foslie. Weber van

Bosse and Foslie, 1904, /Si&ogra-Expeditie Mon. 61, p. 73-

77, figs. 30-32. 

Melobesia (Lithoporella) melobesioides Foslie. Lemoine, 1939,

Mat. Carte ge"ol. de 1'Algerie, ser. 1, Paleont., no. 9, p.

108-110, figs. 78, 79. 

Lithoporella melobesioides (Foslie) Foslie. Lignac-Grutterink,

1943, Geol.-mijnb. genootsch. Nederland en Kolonien

Verh., Geol. ser., v. 113, p. 292-293, pi. 2, fig. 8. 

Lithoporella (Melobesia) melobesioides (Foslie) Foslie. Johnson

and Ferris, 1949, Jour. Paleontology, v. 23, no. 2, p. 196-

197, pi. 37, figs. 4-5; pi. 39, fig. 2. 

Lithoporella melobesioides (Foslie) Foslie. Johnson and Ferris,

1950, B. P. Bishop Mus. Bull. 201, p. 18, pi. 8, fig. A. 

Johnson, 1957, U.S. Geol. Survey Prof. Paper 280-E, p.

234, pi. 37, fig. 5; pi. 43, fig. 1-2; pi. 49, fig. 4; pi. 56, fig. 6.

Description. Thallus single layer of large vertically 

elongated cells, except in vicinity of conceptacles where 

several layers of smaller cells may develop. Cells 

rectangular, commonly with rounded corners. Conceptacles with single large aperture.

The following tables give dimensions of 44 representative specimens from the various limestones of Guam.

Measurements, in microns, of Lithoporella melobesioides 

[From random sections. Cleared entries indicate absence of conceptacles]

Measurements, in microns, of Lithoporella melobesioides Con.

Locality

Cell dimensions

Height Width

Conceptacles

Diameter Height

MIOCENE SPECIMENS Continued 

Bonya Limestone

Fi 3-2(2) .....

Gj 7-2(2) 

29-60 

39-66

9-19 

12-20 616-660 220-264

Alifan Limestone

Eh 3-8- _

Ts9-l(D 

Ts 16-1 

Ts 16-6 

20-33 

49-57 

33-50 

36-70 

18-35 

33-53

11-15 

12-18 

8-11 

9-15 

8-14 

14-28

286 

250-343

105

77-82

Barrigada Limestone

Oq 1-1 ... 

Ov 7-2(2). ..... . .....

22-28 

25-45

9-18 

11-18

PLIOCENE AND PLEISTOCENE SPECIMENS 

Mariana Limestone

GMH 1.......... ................

GMH 11 

Hn 7-3(2) 

17-31 

26-40 

53-61

9-13 

10-17 

13-16

119-120 105-106

Locality

Cell dimensions

Height Width

Conceptacles

Diameter Height

EOCENE SPECIMENS

Fk 4-8...........................

Fk 4-11. .........................

Fk 4-11..... _ ..................

Fk4-ll._. ______ ___.

Fk 4-2.... ._-_________...

Fk 4-3... ........................

Fk 4-7. .......................

Fk4-ll.........._____ _

42-53 

26-29 

49 75

26-53 

33-39 

45-59 

37 57

28-58

16-24 

10-19 

10-17 

10-18 

12-20

19 Q1

20-27 

18-27

276

257

227 

550

131

147

150 

200

MIOCENE SPECIMENS 

Maemong Limestone Member of Umatac Formation

Fi 6-1 _______________________

Fi6-4...___. ........._....____...

Fl 6-6.......... _ ..............

Fi 6-6-.. .....................

Fj 2-5... .........................

Fj 2-5-... .................... _

Fj 2-5... .......................

Hi 5-3---._ __ ...... ........

Hil2-3.. ....... ......

116-9. -- . .___ _. _

116-16.-.. ... .. __..__

li 6-17..... _ __

li 6-18...... __. ___ _

116-18...... _ _____ ______ 

li 6-18.. - _._ ________

116-18 ......... ..... ... _

116-32.-. ... _

116-33.....-.... ___

11 6-33_... ....... ...........

116-33.-. 

116-34... 

II 6-37_-_._ ...... ......

li 6-37-... ...... ... _.

Ii6-38.. ..............

35-51 

40-66 

59-77 

61-96 

58-63 

51-60 

56-65 

28-40 

55-69 

37-57 

39-48 

44-59 

90-97 

61-63 

73-89 

48-63 

34-56 

41-43 

44-56 

50-59 

37-55 

38-49 

31-54 

41-47

15-26 

10-17 

29-59 

16-30 

18-26 

19-27 

14-16 

13-17 

30-34 

20-28 

18-27 

16-25

O9 OQ

19-21 

15-23 

28-35 

18-21 

18-23 

23-29 

18-20 

11 17

51-70

11-26 

16-21

280 

350 

309

188 

150 

216

Remarks. It is quite possible that several true 

species may be grouped together in this assemblage, 

but at present it is not possible to separate them.

The Pliocene and Pleistocene specimens have an 

appreciably smaller average cell size but form an overlapping series with the Miocene specimens (pi. 4, fig. 4).

Occurrence: Eocene to Recent. Localities are given in the 

tables.

Lithoporella sp. A

Plate 10, figure 2

Description. A typical Lithoporella consisting of a 

single layer of vertically elongated cells; a fragment of 

a young and infertile thallus. Cells are unusually 

long, 104M-128M by 36/^-46^.

Remarks. This form has the largest cells observed in 

any Tertiary specimen. The material available, however, is inadequate to justify giving it a specific name.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Loc. Gj 4-4 (D908). 

Figured specimen: A768.

Genus DERMATOLITHON Foslie, 1899

In this genus the plants develop very thin crusts, 

circular or irregular in outline, that grow on other 

algae, coral, shell, or almost any hard object. Thalli 

may grow superimposed. The hypothallus consists of 

a single layer of vertically and obliquely elongated 

cells. The perithallus is built of a few layers of nearly 

cubic cells. Conceptacles are slightly to strongly 

convex, with a single large aperture.

The genus has a geologic range extending from 

Eocene to Recent.
G30 GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

Dermatolithon nitida Johnson

Dermatolithon nitida Johnson, 1957, U.S. Geol. Survey Prof. 

Paper 280-E, p. 235, pi. 57, figs. 2-3.

Description. Thallus thin, encrusting, several may 

grow superimposed. Hypothallus single layer of vertically elongated cells 48^-70^ by 12/4-21/4. Perithallus 

few layers of nearly cubic cells 14^-30^ by 13^-24^. 

No conceptacles observed.

Remarks. In general appearance and cell dimensions 

the Guam specimens agree with the material described 

as D. nitida from beds of the same age on Saipan.

Occurrence: Upper Eocene, Alutom Formation. Loc. Fk 4-3. 

Dermatolithon guamensis Johnson n. sp. 

Plate 10, figures 4, 5

Description. Thallus a very thin crust. Hypothallus 

a single layer of obliquely elongated and slightly curved 

cells 18^-36^ by 11/4-18/4. Perithallus 3-5, commonly 

4, layers of cells 18/4-21/4 by 11/4-17/4. A conceptacle 

chamber present on one specimen measured 330M in 

diameter and 237^ high. Inasmuch as section showed 

single large central aperture, it probably showed approximately full diameter.

Remarks. Represented by two specimens, one a 

basal section and the other approximately longitudinal. 

The species differs appreciably in cell size and dimensions of conceptacles from any hitherto described 

Miocene species.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Locs. li 6-28 (D922) and li 6-36 (D926). 

Figured specimens: Holotype A711. Also figured: A700.

Dermatolithon sp. A 

Plate 10, figure 1

Description. Thallus a very thin irregular crust. 

Hypothallus a single layer of vertically and slightly 

obliquely elongated cells 30^-50^ by 14^-19/4. Perithallus two or three layers of nearly cubic cells 24^-28^ 

by 22^-27/u. Conceptacles unknown.

Remarks. This species is close to D. saipanense 

Johnson from the Miocene of Saipan but differs by 

having smaller and narrower hypothallic cells and 

slightly smaller perithallic cells.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Loc. Fj 2-5 (D901). 

Figured specimen: A703.

Dermatolithon sp. B 

Plate 10, figure 3

Description. Thallus thin irregular crust. Hypothallus single layer of elongated cells 40^-54^ by 13/4-16/4 

Perithallus 3-6 layers of nearly cubic cells 19^-23^ by 

4fj,-21fjL. No conceptacles present.

Remarks. Represented by a single specimen in the 

collection studied.

Occurrence: Upper Miocene, Alifan limestone. Loc. Hn 7-3 

(D917).

Figured specimen: A704.

Genus MELOBESIA Lamouroux, 1812

The plant consists of a small thin crust, circular or 

irregular in outline. The thallus consists normally of 

a single layer of cubic or horizontally elongated cells, 

except in the vicinity of conceptacles. Conceptacles 

have several to many apertures in roof for the escape 

of spores.

The genus has a geologic range extending from Eocene 

to Recent and is represented in the Guam collections 

by a single Miocene specimen.

Melobesia guamensis Johnson n. sp. 

Plate 10, figure 6

Description. Thallus a single layer of horizontally 

elongated cells 9^-1IM by 12^-16^. No conceptacles 

present.

Remarks. This is the first Miocene species of this 

genus to be described from the Pacific area. It is 

characterized by the small-sized horizontally elongated 

cells.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Loc. li 6-32 (D923). 

Figured specimen: Holotype A722.

Subfamily CORALLINOIDEAE (articulate coralline algae)

The Guam limestones contain abundant fragments 

of the articulate coralline algae. In a few places these 

algae are so abundant as to be important contributors 

to the rock. In most places, however, they are distinctly subordinate to the crustose coralline algae. 

Their study has presented many problems. The principal difficulty is that the classification of Recent 

forms is based largely on the shape of the plant and on 

the position and nature of the conceptacles, whereas 

the fossils consist almost entirely of fragments, generally 

separate segments of the plants. On a few specimens 

several such segments joined together may be found 

but never enough to give much idea of the size and 

shape of the entire plant. In a study of more than 

5,000 thin sections of limestone from the Pacific, which 

contained many thousands of fragments of articulate 

coralline algae, the author has only seen 15 or 20 

specimens that contained conceptacles. Consequently, 

the only common data that may be obtained from the 

fossils for use in identifying species are the segments, 

their size, shape, and character of tissue, plus the cell 

dimensions of the medullary hypothallus and of the 

marginal cells.
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM

Most descriptions of Recent species give the size and 

shape of the plants and the dimensions of some of the 

segments, but very few give the size of the cells, except 

in the nodes. Also, most Recent genera and species 

show a considerable range in size and even in the shape 

of the segments. The shape may vary considerably 

according to the position of the particular segment in 

the plant.

The key to genera given below attempts to emphasize as many of the features that are found in fossils as 

possible, but it will be noted that great emphasis is 

placed upon the conceptacles and the nodes, features 

which are seldom preserved in the fossils. This key 

is based largely on the work of Manza and Yendo.

Relatively few species of articulate coralline algae 

have been described as fossils. However, it is difficult 

to compare material with most of these as some of the 

descriptions are altogether too brief, whereas others 

have been based on single segments and are quite 

useless.

Fourteen species belonging to five genera have 

been recognized from the Guam limestones.

Key to the important genera of the articulate Coralline algae

[J. Harlan Johnson, 1956]

Segments consist of several or many tiers of cells, II 

Segments consist of a single tier of long cells. .-Lithotrix 

Each tier composed of regular cells with straight 

walls __ ___________________________________ III

Tiers composed of irregular, sinuous, and interlacing cells. (Conceptacles lateral. Nodes 

formed of a single tier of cells)______ l Calliarthron

Boundaries between tiers of cells essentially

regular. _ _________________________________ IV

Boundaries between tiers of cells irregular, commonly more or less stepped. Cells commonly 

wedge shaped. Segments small, slender, cylindrical. Conceptacles terminal-___------__ l Jania

IV. a. Tiers of cells of principally the same length_____ V

b. Commonly tiers of long and short cells variously 

alternating. Segments show considerable variation in size and some variation in shape. Commonly they are cylindrical or flattened cylindrical. Nodes rather inconspicuous, of one or 

several tiers of cells. Conceptacles lateral

1 Amphiroa

V. a. Tiers of cells gently but evenly arched- ________ VI

b. Tiers of cells flattened in central area, curving 

downward sometimes abruptly, toward the 

margins. Nodes cf a single tier of cells, 

Branching regular, pinnate. Conceptacles 

are terminal, __ ____________________ * Arthrocardia

VI. a. Segments not of same shape in different areas of

the same plant__ __________________________ VII

b. Segments cylindrical or flattened cylindrical. In 

section commonly wider at top than at base. 

Nodes conspicuous with a single tier of very 

long cells. Branching commonly in a plane, 

pinnate. Conceptacles terminal------- * Corallina

b.

III. a.

b.

' Calliarthron, Jania, Amphiroa, Arthrocardia, and Corallina are the only genera so 

far known to be represented by fossils.

Key to the important genera of the articulate Coralline algae 

Continued

VII. Segments commonly clavate, but may be oval, 

rounded, flattened, or polygonal in section.

1. Bifurcating branching. Conceptacles on margins

of upper lobes of segments_____-___- Cheilosporum

2. Segments commonly cylindrical or nearly so near 

base of the frond, becoming trapezoidal above. 

Branching pinnate. Conceptacles at the end 

of the lateral branches.___________---_ Joculator

3. Segments cylindrical or compressed cylindrical 

below, becoming flattened above with oval 

cross section. Branching dichotomous or 

alternating. Nodes consist of a single zone of 

cells. Conceptacles lateral._____________ Bossea

Genus CALLIARTHRON Manza, 1937

This genus suggests Corallina but differs in that the 

cells of the medullary hypothallus instead of being 

straight are flexuous and interlacing. Segments are 

commonly rather short as compared to the width. 

Nodes conspicuous, of a single tier of very long cells. 

Conceptacles develop along the sides of the segments.

The genus is known from the Miocene to the Recent.

Calliarthron antiquum Johnson

Calliarthron antiquum Johnson, 1957, U.S. Geol. Survey Prof. 

Paper 280-E, p. 237, pi. 52, figs. 1, 9.

Description. Segments 217/U-440M long by 440 M~ 

705/i wide; contain 5-8 tiers of cells. Hypothallic cells 

near center measure 51/--73M by S^-lQu. Nodes large, 

22/--270/- high by 315/--417M wide, cells 220/r-260M long. 

Marginal cells abraded. No conceptacles present.

Remarks. A number of fragments were observed 

in the Guam collection, including several which contained 2 and 4 connected segments. They are identical 

with the species described from Saipan.

Occurrence. Lower Miocene, Maemong Limestone Member 

of Umatac Formation. Loc. Fi 6-4.

Genus AMPHIROA Lamouroux, 1812

The plants develop as clusters of segmented fronds 

that branch dichotomously or trichotomously at 

regular intervals. The segments are cylindrical to 

flattened or may develop a relatively thick center and 

thinner margin. The segments consist of a welldeveloped medullary hypothallus and a marginal perithallus. In Recent and most fossil species, the medullary hypothallus is built up of arched layers of cells 

that show rhythmic alternations of layers of long cells 

and layers of short cells. In a given species this seems 

to follow a quite definite formula. In some of the very 

ancient species from the Upper Cretaceous and Eocene, 

the formula is less definite. The alternation of layers 

of long cells and layers of short cells is expressed as a 

formula L-S. For example, 3L-1S means 3 layers of
G32 GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

long cells are followed by 1 layer of short cells. In 

the tables merely the numbers are shown, 3L-1S is 

shown as 3-1. Variable alternations are shown by a 

sequence, for example, 3L-1S, 4L-1S, 5L-1S.

Some species contain very long cells. In fact, the 

longest cells found in any 'of the coralline algae occur 

in the genus Amphiroa. Normally the marginal perithallus is moderately to well developed, although in a 

few species it is reduced to one or two layers of cells. 

The conceptacles are lateral.

The genus has a geologic range extending from the 

Cretaceous to the present. It is abundantly represented by a number of species in the seas today. Some 

of these are very widespread.

Seven species were recognized in the limestone from

Guam.

Amphiroa anchiverricosa Johnson and Ferris

Plate 11, figures 9, 10

Amphiroa anchiverricosa Johnson and Ferris, 1950, B. P. Bishop

Mus. Bull. 201, p. 19, pi. 5, fig. D; pi. 7, fig. C. 

Ishijima, 1954, p. 61-62, pi. 39, figs. 2, 3.

Description. Segment lengths more than 3.3 mm, 

widths ranging 1.0-1.37 mm; wide medullary hypothallus, well-developed marginal perithallus. Hypothallus of gently arched layers of cells, formula IL-lS; 

long cells 42Ai-104/x by S/x-lS/x, short cells 22/X-55/X by 

Gtj,-15n. Marginal perithallus 117/X-220M thick with 

cells lOju-26/x by 8/x-15/x. Conceptacles unknown.

Detailed measurements, in microns, of Amphiroa anchiverricosa Johnson and Ferris

[From random sections]

Locality

Gi 2-7

Gi4-l________________

Gj 7-2___. ___________

Ih5-6._______________

Ih 5-6. _ ________ ___

Range- _ _ _ _

Formula L-S

1-1 

1-1 

1-1 

1-1 

1-1

Long Cells

Length

78-104 

49-61 

48-84 

42-50 

72-90 

42-104

Width

9-11 

10-12 

8-11 

9-13

8-9 

8-13

Short Cells

Length

27-33 

39-50 

22-41 

22-27 

32-55 

22-55

Width

9-15 

8-10 

6-11 

9-11 

8-10 

6-15

Marginal Cells

* Length

12-25 

14-26 

10-14 

10-16 

10-26

Width

8-10 

8-11 

9-12

8-15 

8-15

Hypothallus

Diameter

1,056 

1,077 

1, 276 

1,000 

1,060

Perithallus

Thickness

220 

210

117

Remarks. This distinctive form is the same as that 

described as A. anchiverricosa by Johnson and Ferris 

from the Miocene of Lau, Fiji. It is moderately abundant in the Bonya Limestone of Guam.

Occurrence: Lower Miocene, Bonya Limestone. Locs. Gi 

2-7 (D905), Gi 4-1, Gj 7-2 (D909), and Ih 5-6. 

Figured specimens: A742 and A713.

Amphiroa prefragilissima Lemoine

Plate 11, figures 2, 3, 5, 11

Amphiroa prefragilissima Lemoine, 1917, Soc. geol. France Bull., 

ser. 4, v. 17, p. 275-277, fig. 23.

Description. Highly variable species, segments attain lengths of several millimeters, diameters 136/X-698M,

(commonly 400AI-500/X). Medullary hypothallus shows 

variable formula (both in different segments and a 

single long segment), some 3L-1S; some 4L-1S; some 

4L-1S, 5L-1S; one 2L-1S, 3L-1S, 4L-1S, 5L-1S, 

6L-1S, 7L-1S; another 5L-1S, 7L-1S; and one 7L-1S, 

8L-1S, 7L^1S; most 4Lr-lS. Cells also show great 

size range; long cells 32^-108^ by Sfji-lQ/j., short cells 

HM-^'IM by 9/^-15/u. Marginal perithallus commonly 

present, 1-8 layers of cells, commonly 3 or 4; cells 

13-23 (38) M by 7fj.-15iJ,. Conceptacles suggested on one 

specimen (pi. 11, fig. 11), marginal with diameters 

300M-325MDetailed measurements, in microns, of Amphiroa prefragilissima Lemoine

[From random sections]

Locality

Eh 3-3___________________

Eh 3-3_________________

Eh 3-8______________ __

Eh 3-8____ ___ _

Ts 9-l_____ ____ _

Ts9-l___ ___ __

Ts 16-1________________

Ts 16-6________ _

Ts 16-9___ ___

Ts 16-9 _

Ts 16-11_______ ___ __

Formula L-S

7-1, 8-1, 7-1..---

2-1, 3-1, 4-1, 5-1, 

6-1. 

4-l______________

5-1, 3-1, 5-l--____

4-1

4-l______________

*v-1 7-1

4_1 5_i 4_i

5-l_--____-______

3-1, 4-l__________

4_1 4_i 5_i

Long cells

Length

73-95

48-84

65-90

68-81 

54-102 

58-108 

52-88 

90-110 

34-80 

50-78 

32-78

Width

7-11

8-12

9-10 

12-14 

9-11 

11-14 

9-16 

10-15 

10-15 

9-12 

10-13

Short cells

Length

32-38 

11-41

25-54 

16-30 

23-31 

23-28 

17-25 

23-28 

16-23 

14-21 

15-26

Width

9-13 

9-13

9-11 

10-13 

9-16 

12-15 

11-14 

11-16 

10-15 

8-13 

8-13

Marginal cells

Length

13-18

C)

(? )

15-25 

15-25 

12-15 

12-23

13-23 

23-38 

14-21

Width

12-15 

7-9 

7-10 

8-11

7-11 

7-13 

7-11

Segment 

diameter

435 

215

250 

350-450 

600-650 

800 

453 

502 

675 

700 

700

Conceptacle 

diameter

285-347

Marginal cells absent. 2 Marginal cells worn off.
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM G33

Remarks. This species fits Lemoine's species from 

the upper Tertiary of Martinique and closely resembles 

the highly variable Recent species A. fragilissima 

(Linnaeus) Lamouroux.

Occurrence: Upper Miocene, Alifan Limestone. Locs. Eh 

3-3 (D892), Eh 3-8 (D893), Ts 9-1, Ts 16-1 (D937), Ts 16-6, 

Ts 16-9 (D942), and Ts 16-11.

Figured specimens: A747, A767, A760, and A761.

Amphiroa cf. A. regularis Johnson and Ferris 

Plate 11, figure 1

Amphiroa regularis Johnson and Ferris, 1950, B. P. Bishop Mus. 

Bull. 201, p. 20, pi. 5, fig. E; pi. 8, fig. E.

Description. Segments 1,700^-1,950^ long. Medullary hypothallus formula 3L-1S, 3L-1S, 2L-1S, 3L-1S, 

with long cells 43^-87^ by 10^-15^, short cells 16^-35^ 

by 9/x-13/x with 27 cells to the row. Marginal perithallus 2 or 3 rows of cells 18/--26/- by 8/--13/*. No 

conceptacles present.

Remarks. This form resembles A. regularis in formula and cell dimensions. It differs in the structure 

of the marginal perithallus which is composed of a 

single layer of marginal cells in A. regularis but contains 

several layers of cells in the Guam specimens.

Occurrence: Upper Miocene, Alifan Limestone. Loc. Tt 7-4 

(D944).

Figured specimen: A769.

Amphiroa tan-i Ishijima

Plate 11, figures 6, 12 

Amphiroa tan-i Ishijima, 1954, p. 55-56, pi. 41, figs. 1-3.

Description. Segments slender, lengths more than 

1.6 mm, diameters 200^-250^; medullary hypothallus 

surrounded by single layer of marginal cells; layers of 

cells have formula 5L-1S, 4L-1S; layers commonly 

flattened on top, then arching sharply at edges. Long 

cells 45/--86M by 9^-13^, short cells 17^-40^ by 9^-19^. 

Marginal cells 14/r-25/* by 8^-18^. Conceptacles 

unknown.

Detailed measurements, in microns, of Amphiroa Tan-i Ishijima 

[From random sections]

Locality

Ih 14-1______ ______ _

Ih 14-2___. ___________

Ih 14-2____________

Ih 5-6________________

Formula L-8

5-1 

3-1, 5-1 

5-1 

4-1, 3-1

Long cells

Length

45-77 

65-81 

72-86 

65-77

Width

8-13

9-13

9-16

Short cells

Length

17-26 

24-35

27-40 

21-41

Width

9-13 

10-19

9-15

Marginal cells

Length

18-25 

14-16

Width

8-13 

14-18

Hypothallus 

diameter

220-242 

211 

250 ± 

230

Segment 

diameter

225-250 

239

235

Remarks. This appears to represent the same species 

as described by Ishijima from the Miocene of Formosa. 

Isijima's material appears to have been badly abraded, 

whereas the Guam fragments are broken but have 

suffered little wear and consequently show details absent 

on the type material. However, the most characteristic features slender rather flexuous segments, virtual 

absense of a marginal perithallis, and flat tops of the 

medullary cell layers are the same. The cell dimensions are of the same magnitude, although slightly 

wider in the Guam specimens. The Formosa specimens 

have a formula of 3L-1S, 5L-1S, whereas most of the 

Guam specimens have 5L IS.

Occurrence: Lower Miocene, Bonya Limestone. Locs. Ih 14-1 

(D930), Ih 14-2 (D931), and Ih 5-6 

Figured specimens: A730 and A770.

Amphiroa cf. A. verricosa Etitzing 

Plate 11, figure 7

4.mphiroa verricosa Ktitzing, 1845-71, Tab. Phye, v. 8, p. 25,

pi. 51. 

Pfender, 1924, Soc. g<5ol. France Bull., ser. 4, v. 24, p. 194,

pis. 8-9. 

Ishijima, 1954, p. 62, pi. 37, figs. 12-16.

Description. Fragments of long relatively wide segments, formula 1L-1S (in a few 2L-1S). Segments 

550/--650M wide. Long cells 64/X-108M by Q/jL-l5n, 

short cells 21/,-42/x by 9/r-lS/,. No marginal cells 

present. Conceptacles unknown.

Remarks. Represented by small worn fragments in 

the Guam collection. In appearance, formula, and 

cell dimensions, this form closely resembles the Recent 

A. verricosa Ktitzing. Similar material attributed to 

the same species has been described by Ishijima (1954, 

p. 62) from the Pliocene of Formosa.

Occurrence: Upper Miocene, Barrigada Limestone. Loc. Ov 

7-2 (D933).

Figured specimen: A771.

Amphiroa sp. C

Plate 12, figure 5

Description. Segments 1.1-1.6 mm long, composed 

entirely of a medullary hypothallus consisting of alternate layers of long and short cells. Long cells 63/--70/, 

by 27^-33^, short cells 27^-33^ by HM-^M. Cell walls 

unusually thick and prominent; in section about 28 cells 

form layer. No marginal cells or conceptacles present.

688S76 O 6£
G34 GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

Remarks. In cell lengths and formula (1L-1S) this 

resembles A. anchiuerricosa Johnson and Ferris described 

from the upper Miocene of Fiji and by Ishijima from the 

Pleistocene of Formosa, but it differs from them by having much wider cells (2 to 3 times as wide) and by having 

much thicker and more conspicuous cell walls.

Represented by only a few worn fragments in the 

Guam collection which are inadequate to name the 

species.

Occurrence: Pleistocene, fore-reef fades of the Mariana Limestone. Loc. Ji 1-1 (D932). 

Figured specimen: A773.

Amphiroa sp. D

Plate 11, figure 8

Amphiroa regularis Johnson and Ferris, 1950, B. P. Bishop Mus. 

Bull. 201, p. 20, pi. 5, fig. E; pi. 8, fig. E.

Description. Fragments of segments having a formula of 2L-1S or 3L-1S; segments 187^-357^ wide; long 

cells 34^-60^ by 8/x-14/x, short cells 9^-22^ by 8/*-12/x. 

Cortical layer badly abraded or absent. No conceptacJes observed.

Remarks. Represented in the Guam collections by a 

number of small fragments. These strongly suggest but 

are not identical with the material described as A. 

regularis by Johnson and Ferris from the upper Miocene

of Lau, Fiji, which had somewhat larger cells and had a 

2L-1S formula more commonly than a 3L-1S.

Occurrence: Upper Miocene, Barrigada Limestone. Locs. Oq 

1-1 and Rx 8-2 (D935).

Figured specimen: A774.

Genus CORALLINA Linnaeus, 1758

Plants small, bushy, composed zof segmented stems 

that branch frequently (normally in a plane); branching pinnate. Segments cylindrical or flattened, commonly wider at top than at base. Nodes conspicuous, 

consisting of a single tier of very long cells. Segments 

consist mainly of medullary hypothallus surrounded 

by a thin layer of perithallic tissue.

The genus has a geologic range extending from the 

Late Cretaceous to the present time. Fossil Corallina 

was observed in most of the Guam limestones and 

was locally abundant.

Corallina matansa Johnson

Corallina matansa Johnson, 1957, U.S. Geol. Survey Prof. Paper 

280-E, p. 238-239, pi. 44, figs. 3, 4.

Description. Segments flattened, moderately wide, 

mainly hypothallic tissue. Cells in center of hypothallic layers 52^-66^ by 7j«-l IM- Perithallic cells 

10^-22^1 by 7j«-l I/JL; 20-28 tiers of cells to a segment. 

Size of node 125^ by llOju.

Detailed measurements, in microns, of Corallina matansa Johnson 

[From random sections. Cleared entries indicate absence of nodes]

Locality

Fk 4-3

Fk 4-3_-____-___

Fk4-4___ __

Fk 4-8 _

Segment size

Length

1,465 

1,700 

1, 672 

1,350

Width

418 

200 

352 

350

Hypothallus cells

Length

60-66 

52-60 

62 

60-62

Width

7-11 

10-11 

8-10 

9-10

Perithallus cells

Length

10-22

Width

7-11

Tiers of cells 

in a segment

26

28 

28 

20

Node size

Length

125

Width

110

Remarks. These are identical with the material 

described from Saipan.

Occurrence: Upper Eocene, Alutom Formation. Locs. Fk 

4-3, Fk 4-4, and Fk 4-8.

Corallina prisca Johnson

Corallina prisca Johnson, 1957, U.S. Geol. Survey Prof. Paper 

280-E, p. 239-240, pi. 37, fig. 4; pi. 40, fig. 10; pi. 44, figs. 

1-2. 7-11.

Description. Segments slender, nearly cylindrical, 

commonly slightly flattened, largely medullary hypothallus surrounded by a layer or two of perithallic cells. 

Cells near center of hypothallic tiers 65^-101^ by 

7/z-12/z.

Remarks. The specimens from Guam appear to be 

identical with those described from Saipan.

Occurrence: Upper Eocene, Alutom Formation. Locs. Fk 4-3, 

Fk 4-8, and Fk 4-11.

Detailed measurements, in microns, of Corallina prisca Johnson 

[From random sections. Cleared entries indicate absence of nodes]

Locality

Fk 4-3-... 

Fk4-3 .... _.

Fk4-8 .. ....

Fk 4-11-.------

Segment size

Length

752 

2,600 

546 

1,500

Width

176 

350 

211 

450

Hypothallus cells

Length

65-91 

80-90 

41-101 

67-70

Width

9-11 

9-11 

7-11 9-12

Tiers of 

cells in a 

segment

11 

30

8

Node size

Length

150

Width

200
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM G35

Corallina neuschelorum Johnson

Corallina neuschelorum Johnson, 1957, U.S. Geol. Survey Prof. 

Paper 280-E, p. 239, pi. 37, fig. 3; pi. 50, figs. 1-4.

Description. Segments normally flattened clavate, 

consisting mainly of hypothallic tissue. Cells in

center of tiers 47^-107ju long by Q/j,-20fjL wide (commonly Sfji-Wfj,). Perithallus slightly developed, normally single layer of marginal cells 10M-26juby 7fj,-l2,fjL. 

Conceptacles present on three specimens, two marginal 

and one terminal; marginal conceptacle diameters 

7lfjL-l50fjL and heights

Detailed measurements, in microns, of 17 specimens of Corallina neuschelorum Johnson 

[From random sections. Cleared entries indicate absence of nodes]

Locality

Fi 6-4_. _--____

Fi 6-6___._-___

Fi 6-7- 

Fi6-7___ 

Fi 6-7_-_----__

Fj 2-4______-__

Hi 5-2_-_______

Hi 5-3___--____

Hi 12-2 

Hi 12-3________

li 6-13 ------

li 6-25 -__-__

li 6-26 ------

li 6-26 ---__-

li 6-26 -___--

li 6-26 ------

li 6-31.. ---_-_

Segment size

Length

256-270 

365-630 

194-272 

213-337 

709 

1181 

611-629 

1276 

698 

770 

396-796 

616 

1100 

378 

759 

616-602 

516-559

Width

194-238 

175-210 

160-163 

123-141 

203 

596 

426-460 

652-636 

308 

264 

264-308 

206 

520 

308 

455 

440-475 

321-440

Node size

Length

129-136 

101-120 

96 

62-96

168

Not preserved

Not preserved

255 

215

Width

171 176

106 

75-96

205 

220

352 

303

Hypothallus cells

Length

55-82 

53-61 

36-62 

42-72 

63-82 

81-99 

51-61 

37-48 

44-69 

94-119 

48-92 

26-80 

45-90 

51-65 

62-84 

47-107

50-77

Width

7-9 

10-12 

6-10 6-9 

5-9 

8-10 

8-11 

13-20 

7-10 

10-14 

8-13 

7-10 

8-11 

7-10 

7-12 

7-11 

7-10

Perithallus cells

Length

9-15

21-26

18-22

Width

9-10

7-11

11-12

Tiers in a 

segment

5 

8-10 

6 

6-14 

10 

15 

11 

29 

7 

7 6-9 

10 

14 

8 

11 

9 8-10

Approximate 

number of 

cells in section 

of tier

26-38 

28-36 

15-19 

20-31 

14-19 

55-60 

35-50 

48 

20-30 

20-25 

30-40 

25 + 

50-60 

30-40 

50 

40-60 

30-50

Remarks. This species is abundantly represented in 

the Maemong Limestone Member at most localities. 

It is the same species originally described from Saipan. 

The details presented here supplement the Saipan data 

and in addition give a knowledge of the conceptacles 

of this species.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Locs. Fi 6-4, Fi 6-6, and Fi 6-7; Fj 2-4,

Hi 5-2, and Hi 5-3; Hi 12-2 and Hi 12-3; li 6-13, li 6-25, li 6-26, 

and li 6-31.

Corallina sp. A

Plate 11, figure 4; plate 12, figure 6

Description. Segments relatively long and slender, 

about 500M-1300/I long, mainly a medullary hypothallus 

with cells in center of tiers 40ju-78ju long by 6^-1 IM wide. 

Conceptacles unknown. Detailed dimensions of the 

five best specimens observed are given as follows.

Detailed measurements, in microns, of Corallina sp. A Johnson 

[From random sections. Cleared entries indicate absence of nodes]

Locality

Hn 7-l_---_- __

Hn 7-1

Hn 7-2

Hn 7-2 ______ _ _ _

Hn 7-2______ __ 

Segment size

Length

854 

924 

1,254 

513

481

Width

220

282 

343 

422

284

Node size

Height

106

Width

198

Hypothallus cells

Length

51-74 

57-78 

42-53 

40-55 

42-56

Width

8-11 

7-11 6-11

Tissue of 

cells in a 

segment

13-14 

16 

30 

13

7

Approximate 

number of cells 

in a section 

across a tier

26-30 

35-40 

50

28 

40

Remarks. The specimens included in this group all 

have dimensions that fall within the range of those given 

for C. neuschelorum. However, the segments are commonly longer, and the cells of the medullary hypothallus 

are considerably shorter (range 42^-78^ versus 47ju107ju). With only a few specimens available for study

and considering the considerable range in size of segments and cells in Recent species, it does not seem 

desirable to give it a specific name.

Occurrence: Upper Miocene, Alifan Limestone. Locs. Hn 

7-1 (D915) and Hn 7-2 (D916). 

Figured specimens: A775 and A776.
G36 GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

Genus AETHROCARDIA Decaisne, 1842, emend. 

Areschoug, 1850

In scanning the great numbers of fragments of 

articulated coralline algae present in the slides of Guam 

limestones, a few that belong to the genus Arthrocardia 

were observed. They occurred in the Eocene and 

Oligocene Alutom Formation and in the lower Miocene 

Maemong Limestone Member of Umatac Formation. 

However, the material was inadequate to permit 

description of the species represented.

Genus JANIA Lamouroux, 1812

The plants form small bushy masses of tiny slender 

fronds which branch dichotomously. Each frond consists of a series of relatively long, slender segments 

formed of tiers of hypothallic cells surrounded by a 

single layer of small rectangular cells. The hypothallic 

cells are commonly wider in proportion to their length 

than in other genera of articulated corallines and tend 

to be wedge shaped in longitudinal sections. The 

junction between the tiers is seldom smooth. It 

frequently is very irregular. The segments are commonly longer and relatively more slender than in most 

articulated corallines.

Today Jania is represented by many species in the 

tropical and temperate seas. It is known from the 

Late Cretaceous to the Recent time.

Fragments attributed to this genus were observed in 

Guam limestones ranging in age from Eocene to Pleistocene, but the only material adequate for description 

was found in some of the Miocene limestones.

Jania vetus Johnson

Jania vetus Johnson, 1957, U.S. Geol. Survey Prof. Paper 280-E, 

p. 237, pi. 52, fig. 2.

Description. Segments l,395/i-l,585/i long by 394/4- 

448/i wide. Hypothallic cells 66/i-77/i by ll/i-20/i. 

Marginal cells 13/*-17/* by 18/i-25/*.

Remarks. Represented by a few fragments in the 

Guam collection. These are identical with the specimens described from Saipan.

Occurrence: Lower Miocene, Maemong Limestone Member of 

Umatac Formation. Loc. Fi 6-5.

Jania guamensis Johnson n. sp. 

Plate 12, figures 1-3

Description. Segments attaining lengths of at least 

3,000/i. Hypothallic cells 32/U-46/* by lO/u-22/i (commonly 36/i-40/i by 10*1-18/0. Dimensions of six 

typical specimens are given in the table.

Locality

Segment size

Length Width

Hypothallus cells

Length Width

Perithallus cells

Length Width

Maemong Limestone Member of Umatac Formation

Fd 4-1. 

Fd4-l 

Hi 12-3..... . 

li 6-25...... 

Ii6-26 

Ii6-26 

1, 250+ 

968+ 

3,080 

1, 320+ 

2, 034+ 

1,452

247 

246 

294 

250 

287 

345

39-46 

39-45 

31-40 

32-40 

36-48 

37-53

13-18 

10-18 

14-18 

9-18 

14-18 

15-22 14-19 10-13

Bonya Limestone

Ih 14-1... .......... 1,400+ 350 27-41 16-21 14-19 13-18

Detailed measurements, in microns of Jania guamensis Johnson

n. sp.

[From random sections. Plus sign Indicates fragments of segments not showing 

total length]

Remarks. The only other described Miocene species 

of Jania known by the author is J. vetus Johnson from 

Saipan. It differs from the present species by having 

much longer hypothallic cells (54/*-78/u versus 32/i46/0.

Occurrence: Lower Miocene, Maemong Limestone Member 

of Umatac Formation. Locs. Fd 4-1 (D897), Hi 12-3 (D913), 

Ji 6-25, and li 6-26 (D920). And Lower Miocene, Bonya 

Limestone. Loc. Ih 14-1.

Figured specimens: Holotype A777. Also figured: A778 and 

A714b.

CHLOROPHYTA (green algae)

The Chlorophyta are represented in the Guam 

collections by two genera belonging to two different 

families, the Codiaceae and the Dasycladaceae.

Family DASYCLADACEAE

Dasycladaceae are rare in the Guam limestones. 

These were studied and described by Richard Rezak, 

U.S. Geological Survey, who contributed data for the 

following description.

Genus CYMOPOLIA Lamouroux, 1816

Cymopolia cf. C. pacifica Johnson

Plate 12, figures 9, 10

Cymopolia pacifica Johnson, 1957, U.S. Geol. Survey Prof. 

Paper 280-E, p. 240, pi. 45, figs. 1-12.

Description. Thallus consists of series of short 

nearly cylindrical segments 1.39 mm long by 1.53 mm 

wide, containing central stem 0.4-0.6 mm thick, 

surrounded by regular whorls of primary branches. 

Diameter of primary branches 35/*-47/u, whorls spaced 

93ju apart. Tufts of secondary branches inflated at 

ends forming cortex. Sporangia ovoid size 121/u by
FOSSIL AND RECENT CALCAREOUS ALGAE FROM GUAM G37

173n to 155ft by 242n, located at apices of primary 

branches between secondary branches.

Remarks. This is very close to C. pacifica Johnson 

described from Saipan. The Guam material is too 

scarce and fragmentary to permit exact determination.

Occurrence: Eocene Alutom formation. Loc. Fk 4-9 (D902). 

Figured specimen: A772.

Family CODIACEAE 

Genus HALIMEDA Lamouroux, 1812 

Plate 12, figures 4, 8

Plants belonging to this genus are composed of 

segmented branching stems or fronds. The segments 

take on a variety of shapes. They may be broad and 

leaflike, flattened, subcylindrical, or even subconical. 

The older segments become strongly calcified. Calcification starts at the outside of a plant and works inward. 

In very old specimens it may be complete, but in most 

of the specimens observed only the outer part is calcified. 

Consequently, the internal structure may not be shown. 

The classification of Recent species is based largely on 

the branching habit, the shape of the segments, and, 

particularly, on the structure of the node. The fossils 

normally consist of individual segments with little or 

no indication of the structure of the node. Therefore, 

in thin sections which show random cuts through the 

segments, it is, for all practical purposes, impossible 

to distinguish species. The generic structure is very 

distinctive and Halimeda segments, as such, can be 

recognized easily, but beyond that, little can be done 

with fragmentary fossil material.

The genus has a geologic range extending from the 

Cretaceous to the Recent. It is abundantly represented by numerous species in tropical and warmtemperate seas. Locally the plants may grow in 

enormous numbers and literally cover large areas of 

shallow sea bottom.

Halimeda fragments are recognized in the limestones 

of Guam, ranging in age from Eocene to Pleistocene. 

However, it is only in the Pleistocene rocks that they 

occur in such abundance as to form true Halimeda 

limestones.

Occurrence: Eocene, Alutom Formation. Loc. Fk 4-2. Lower 

Miocene, Maemong Limestone Member of Umatac Formation. 

Loc. Gj 4-1 (D907). And Pliocene and Pleistocene, Mariana 

Limestone. Loc. Uu 1-1 (D945).

Figured specimens: A780 and A781.

REFERENCES CITED

Airoldi, Marco, 1932, Contributo allo studio delle Corallinacee del 

terziario Italiano. Part 1 Le Corallinacee dell' Oligocene 

Ligure-Piemontese: Palaeontographia Italica, Mem. Palaeont., v. 33 (new ser. v. 3), p. 55-83, pis. 9-12 [1933].

 1933, Le Corallinacee del Pleistocene della Somalia

Italiana. Part 6 Fossili del Pliocene e del Pleistocene:

Palaeontographia Italica, Mem. Palaeont., v. 32, supp. 1,

p. 79-96 (25-42), pis. 7, 8, (2, 3), text figs. 9-11. 

Areschoug, J. E., 1850, Enumeratio phycearum in maribus

Scandinaviae cresentium: Nova Acta Regiae Soc. Sci.

Upsaliensis, v. 14. 

Barton, E. S., 1901, The genus Halimeda: Si&ogra-Expeditie Mon.

60, p. 1-32, pis. 1-4. 

Capeder, Guiseppe, 1900, Contribuzione allo studio dei Lithothamnion terziari: Malpighia, v. 14, p. 172-182, pi. 6. 

Cloud, P. E., Jr., Schmidt, R. G., and Burke, H. W., 1956,

General geology of Saipan, Mariana Islands: U.S. Geol.

Survey Prof. Paper 280-A, p. 1-126, pis. 1-25, figs. 1-10

[1957]. 

Cole, W. S., 1963, Tertiary larger Foraminifera from Guam:

U.S. Geol. Survey Prof. Paper 403-E. 

Conti, Sergio, 1943, Contributo allo studio delle Corallinacee

del terziario Italiano. Part 2 Corallinacee del Miocene

Ligure-Piemontese: Palaeontographia Italica, Mem. Palaeont., v. 41 (new ser. v. 11), p. 37-61, pis. 5-8, figs. 1-3. 

Decaisne, J., 1842, Essais sur une classification des algues et des

polypiers calciferes de Lamouroux: Annals sci. nat., ser. 2,

v. 17, p. 297-380. 

Doty, M. S., 1957, Rocky intertidal surfaces (ecology of):

Geol. Soc. America Mem. 67, v. 1, p. 535-585, 1 pi., 18 figs. 

Elliot, G. F., 1957, Subterraniphyllum, a new Tertiary calcareous

alga: Palaeont., London, v. 1, pt. 1, p. 73-75. 

Emberger, Louis, 1944, Les plantes fossiles dans leurs rapports

avec les ve"getaux vivants: Paris, Masson et Cie., 492 p.,

457 figs. 

Emery, K. O., Tracey, J. I., Jr., and Ladd, H. S., 1954, Geology

of Bikini and nearby atolls. Part 1 Geology: U.S. Geol.

Survey Prof. Paper 260-A, p. 1-264, pis. 1-73, figs. 1-84. 

Foslie, M. H., 1898, List of species of the Lithothamnia: Det.

K. norske vidensk. selsk. Skr., no. 3, p. 1-19.

 1899, Notes on two Lithothamnia from Funafuti: Det. 

K. norske vidensk. selsk. Skr., no. 2, p. 1-5.

 1900a, Calcareous algae from Funafuti: Det. K. norske 

vidensk. selsk. Skr., no. 1, p. 1-12.

 -1900b, Revised systematical survey of the Melobesieae: 

Det. K. norske vidensk. selsk. Skr., no. 5, p. 1-23.

 1900c, the Lithothamnia of the Maldives and Laccadives: 

The Fauna and Geography of the Maldive and Laccadive 

Archipelagoes: v. 1, pt. 4, Cambridge, p. 460-471, pis. 

24-25.

 1901, New Melobesieae: Det. K. norske vidensk. selsk. 

Skr., no. 6, p. 20-28.

 1909, Algolgiske Notiser VI: Det. K. norske vidensk.

selsk. Skr., no. 2, p. 1-63. 

Foslie, M. H., and Printz, Henrik, 1929, Contributions to a

monograph of the Lithothamnia: Det. K. norske vidensk.

selsk. mus. Mon., 60 p., 75 pis. 

Hauck, Ferdinand, 1878, Beitrage zue Kenntnis der Adriatischen

Algen, in Oesterr: Botanische Zeitschr., v. 28, Wien, p.

288-295, pi. 3, figs. 1-4.

Heydrich, Franz, 1897a, Corallinaceae, insbesondere Melobesieae: Deutsche bot. Gesell. Ber., v. 15, p. 34-70, 403-

420, pis. 3, 18, 3 text figs.

 1897b, Neue Kalkalgan von Deutsch-Neu-Guinea: 

Bibliotheca Botanica, v. 41, p. 1-11, pi. 1-

1902, Sur quelques nouvelles Melobesiees du Museum de

Paris: Mus. Hist. Nat. Paris, Bull., v. 8, p. 473-476.
G38 GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS

Ishijima, Wataru, 1942, Description of two new species of 

Archaeolithothamnium from Taiwan: Taiwan Tigaku Kizi, 

v. 13, no. 4, p. 119-121, 3 text figs. (In Japanese, English 

resume?.)

 1954, Cenozoic coralline algae from the western Pacific: 

Tokyo, Japan [Private publication] 87 p., 49 pis.

Johnson, J. H., 1954a, Fossil calcareous algae from Bikini Atoll: 

U.S. Geol. Survey Prof. Paper 260-M, p. 537-545, pis. 

188-197.

 1954b, An introduction to the study of rock building 

algae and algal limestones: Colorado School of Mines 

Quart., v. 49, no. 2, 117 p., 62 pis.

 1957, Geology of Saipan, Mariana Islands Calcareous 

algae: U.S. Geol. Survey Prof. Paper 280-E, p. 209-243, 

pis. 2, 4, 37-60.

 1963, The use of calcareous algae in correlating Cenozoic

deposits of the western Pacific area: Pacific Sci. Cong.,

9th, Bangkok, 1957, Proc., 

Johnson, J. H., and Ferris, B. J., 1949, Tertiary coralline algae

from the Dutch East Indies: Jour. Paleontology, v. 23,

no. 2, p. 193-198, pis. 37-39.

 1950, Tertiary and Pleistocene coralline algae from Lau, 

Fiji: B. P. Bishop Mus. Bull. 201, 27 p., 9 pis.

Kiitzing, F. T., 1843, Phycologica generalis: Leipzig, 458 p., 

80 pis.

 1845-71, Tabulae phycologicae oder Abbildungen der 

Tange: v. 1-20, Nordhausen.

 1849, Species algarum: Leipzig, 922 p.

Lamarck, J. B., Histoire naturelle des animaux sans vertebras:

Paris, 215 p. 

Lamouroux, J. V., 1812, Classification des Polypiers coralligenes

Nouv.: Soc. Philomat. Sci. Bull. 3, p. 186.

 1816, Histoire des Polypiers coralligenes flexibles: Caen, 

p. 226-302.

 1824, Polypiers flexibles, in de Freycinet, Louis, Voyage 

autour de monde: Zoologie 3, p. 625-628, pis. 93-95.

Lemoine, Mme. Paul, 1917, Corallinacees fossiles de la Martinique: Soc. ge"ol. France Bull., ser. 4, v. 17, p. 256-279, 23 

figs. [1918].

 1923, Melobeisiees Miocene rejcueillies par M. Mourcart 

en Albanie: Soe geol. France Bull., ser. 4, v. 23, p. 273-283, 

text figs. 1-9. 

-1926, Revision des Melobejsiees tertiaries d'ltalie deiscrites

par M. Capeder: Comptes Rendus, Cong., Soc. Savantes 

Sci., 1925, p. 241-259, 17 figs.

 1927, Quelques algues calcaires du Nummulitique de la 

Haute-Savoie: Mus. natl. histoire nat. Bull., v. 6, p. 

545-551, 6 figs.

 1928, Un nouveau genre de Melobejsiees, Mesophyllum-' 

Soc. bot. France Bull., ser. 5, v. 4, p. 251-254.

Lemoine, Mme. Paul, 1930, Les Melobesiees recueillies par M.

Viennot dans le Miocene de la province de Grenade: Soc.

geol. France Bull., ser. 4, v. 29, p. 263-272, 5 text figs.,

pi. 24. [1929]. 

 1934, Algues calcaires de la famille des Corallinacees

recueillies dans les Carpathes occidentales par M. Andrusov:

Czechoslovakia Statniho Geol. Utavu VSstnik, v. 9, no. 5,

p. 269-289, 16 figs. 

-1939, Les algues calcaires fossiles de 1'Algerie: Mat.

Carte geol. de 1'Algerie, ser. 1, Paleont., no. 9, 128 p., 3 pis.,

80 figs. 

Lemoine, J. V., 1940, Les Algues calcaires de la zone neritique,

from Contribution a 1'ejtude de la repartition actuelle et

passee des organisms dans la zone neritique: Soc. Bioge"ographie, Paul Lechevalier, Paris, v. 7, p. 75-128. 

Lignac-Grutterink, L. H., 1943, Some Tertiary Corallinaceae

of the Malaysian Archipelago: Geol.-mijnb. genootsch.

Nederland en Kolonien Verh., Geol. ser., v. 113, p. 283-297,

2 pis., 4 figs. 

Linnaeus, Carl, 1758, Systema naturae, Holmiae, ed. 10, revis.,

v. 1.

 1767, Systema naturae: Stockholm, ed. 12, v. 1. 

Manza, A. V., 1937, The genera of the articulate corallines: 

[U.S.] Natl. Acad. Sci. Proc., v. 23, no. 2, p. 44-48.

 1940, A revision of the genera of articulate corallines:

Philippine Jour. Sci., v. 71, no. 3, p. 239-316. 

Maslov, V. P., 1956, Fossil calcareous algae of the USSR:

USSR Akad. Nauk, Trudy Inst. Geol. Sci., v. 160, 264

p., 86 pis. 

Pfender, Juliette, 1924, Sur une formation Quarternaire marine

des cotes de Provence: Soc. geol. France Bull., ser. 4,

v. 24, p. 193-197. 

Philippi, R. A., 1837, Beweis das die Nulliporen Pflanzen

sind: Archiv. fur Naturgeschichts herausgegeben von

Dr. Wiegmann, v. 3, no. 1, p. 387-393, pi. 9. 

Pia, Julius, 1927, Die Ehrhaltung der fossilen Pflanzen. Part 1 

Thallophyta, in Hirmer, Max, Handbuch der Palaobotanik :

Berlin and Mtinchen, v. 1, p. 1-136, 129 figs. 

Rainer, Rita, 1923, Alghe fossili Mioceniche di Cirenaica:

Nuova Notarisia, v. 35, p. 28-41 [1924]. 

Rothpletz, August, 1891, Fossile Kalkalgen aus den Familien

der Codiaceen und der Corallineen: Deutsche geol. Gesell.

Zeitschr., v. 43, p. 295-321, pis. 15-17. 

Sripada Rao, K., 1943, Fossil algae from Assam: 1. The

Corallinaceae: India Natl. Acad. Sci. Proc., v. 13, p. 15,

p. 265-299. 

Taylor, W. R., 1950, Plants of Bikini and other northern Marshall

Islands: Michigan Univ. Studies, Sci. Ser., v. 18, 227 p.,

79 pis. 

Weber van Bosse, Anna, and Foslie, M. H., 1904, The

Corallinaceae of the Siboga Expedition: Siboga Expeditie

Mon. 61, 110 p., 16 pis., 32 text figs.
INDEX

[Italic numbers indicate descriptions]

Page

abrardi, Lithothamniwm- __ -_ Q5 

AethesoUthon -................ 1, 2, 3, 27

grandis ........ - 3, 4, 6, 8, 9, 27, SS, pis. 9, 10

problematicum........_ 3, 4, 6, 8, #7, 28, pi. 9

aggregatum, Lithothamnium.-................ 2, 5, 11

albanense, Lithophyllum. ........ __ 19, 20

alifanense, Lithophyllum......... 3, 4, 5, 9,16, 17, pi. 3

Lithothamnium.... .. 2, 4, 5, 9, 11, It, pi. 1

aUernatum, LUhophyllum__-- 3, 4, 5, 9, 16, #0, pi. 5 

aUernicellum, Lithophyttum 3, 4, 5, 8, 9, 16, 20, pi. 6 

Amphiroa 2, 6, 22, S/, 32

anchiverricosa-.... .- 3, 4, 6, 8, S#, 34, pi. 11

foliacea-- .. ....... -- 6

fragilissima................................. 6, 33

prefragUissima...... . 3, 4, 6, 8, 9, 32, pi. 11

regularis. 3, 4, 6, 9, S3, 34, pi. 11

tan-i... ----- ....- 3, 4, 6, 9, S3, pi. 11

verricosa ----- 3, 4, 6, 9, S3, pi. 11

sp. C 3, 5, 9, S3, pi. 12

sp. D..... ............... 3, 4, 6, 9, 34, pi. 11

sp. -_ - .____ 4, 6

anchiverricosa, Amphiroa. 3, 4, 6, 8, 32, 34, pi. 11 

antiquum, Calliarthron. -_ - 3, 4, 6, 3.7 

araii, Lithothamnium- ....-- 2, 4, 5, 8,11, ..3, pis. 1, 2

Archaeolithothamnium..... ........... 2, 5, 6, 9, 10

chamorrosum--.._..- _________ 5 

fijiensis . 5 

lauense.. ________ 2, 4, 5, ..0, pi. 10 

liberum........ . ________ 5

lugeoni...-- -- __ 5 

megasporum.- __..._.__ 6 

myriosporum-.-- --.------.-.-_-----_-_- 5

oulianovL - . __ 5 

puntiense...... . .-- __ 2, 4, 5, 6, 10

........................... 2, 5, 10

.......................... 2, 4, 5, ..0

Arthrocardia_--.______________ 2, 31, 36 

sp 2, 3, 4, 5, 6

Articulate coralline algae__________ 31

atjehensis, Rotalia... _______________ 4 

atlantica, Lithopordla 28

aucklandicum, Lithothamnium.. ___-_-____ 6

B 

bamleri, Lithophyttum........................ ___ 20

betieri, Lithothamnium- __________.___ 12

bonyense, Lithophyllum __ 3, 4, 5,9,16,17, 19, pis. 4, 5

Lithothamnium.-.-- ____- 2, 4, 5, 8, JJ, pi. 1

Bossea________-_____________ 31

bourcarti, Lithothamnium..... 2, 4, 5, 8, 11, 12, pi. 1

brevidavium, Goniolithon-............. ________ 26

Calliarthron..... . _______________. 2, 31

antiquum........ _-.-_ _______. 3, 4, 6, 31

chamorrosum, Archaeolithothamnium........ _ _ 5

Cheilosporum ---.____--_-_______ 31 

Chlorophyta_- ..--...-.-. ........_... 1, 2, 36

(Cladolithon) frutescens, Goniolithon- _________ 25

Codiaceae__-______ ___-_.--___ 36, 37

commune, Mesophyllum.-__. 2, 4, 5, 9, 14, pi. 2 

conjuncta, Lithopordla__.___._________ 28

Page 

Corallina...- ----- - ---- 2, 6, 31, 34

matansa-___-____ -__ 2, 3, 5, 34 

neuschdorum.......... _ 3, 4, 6, 35

prisca ----- . - 2, 3, 5, 34

sp. A........ . 3, 4, 6, 8, 35, pis. 11, 12

Corallinaceae. 2, 9 

Corallinoideae------- .- . . . 2, 27, SO

craspedium, Lithophyllum... 24

Lithophyllum (Porolithon).....-------------- 24

Porolithon.-. - . 3, 5, 6, 24

crispatum, Lithothamnium.. .... 2, 4, 5, 11, 14

crispithallus, Lithothamnium.---- 2, 5, 11, IS

cuboides, Melobesia.... 5

cymbicmstum, Lithothamnium.... 5

Cymopolia .- --- 2,36

 2,3, 5,8,36,37,pi. 12

D

Dermatolithon 2, #9

guamensis. .... .-.. .. 3, 4, 6, 8, 9, 30, pi. 10

nitida --. _ - _____ . 2,3,5,6,30 

saipanense 6, 30

sp. A_--__ ___ ------- ___ _-- 3,4,6,8,30, pi. 10

sp. B ___ - ___ -- ___ ---- __ 3,4,6,8,30, pi. 10

sp 

disarmonicum, LithothamniumE

engelhartii, Lithothamnium.- 

expansum, Lithophyllum 

ftjiensis, Archaeolithothamnium-----.. 5

flabelliformis, Lithophyllum moluccense. 8,22, pi. 13 

foliacea, Amphiroa.-.... 6

fosliei, Goniolithon-----. .......... 3,9,24, 25, pi. 13

Lithothamnium.-- 25 

fragilissima, Amphiroa 6,33 

frutescens, Goniolithon ----------- 3,5,6,24, 25, 26

Goniolithon (Cladolithon) _-_-- 25

typica, Goniolithon- . .. 25

fulangasum, Lithophyllum----- 17

fumigatum, Lithothamnium--- 5 

funafutiense, Lithothamnium-- 2,5,6,11, 12

Q

glangeaudi, Lithophyllum- 3,4,5,9,16, 21, pi. 6 

GoT.ioZi.ftoT.- - 2,6,16,23, #4,26

brevidavium- ....- _ __ 26

fosliei 3,9,24, 25, pi. 13

frutescens--... _ ~ 3,5,6,24, 25, 26 

typica ...-----------------.--------.-- 25

laccadivicum.. ...... _ ... 26

medioramus ----------- 3,9,24, 25, 26, pis. 13,15

miocenicum----------------- 3,4, 5,8,24, 26, pi. 8

reinboldi 3,9,24, 26, pis. 13,15

(Cladolithon) frutescens_--------- ----- 25

sp. C- . 3,4,5, 9,24, 27, pi. 8

grande, Mesophyllum____. -- 2,4,5,8,/5, pi. 2

grandis, Aethesolithon .. 3,4,6,8, 9,27, 28, pis. 9,10

Page

guamense, Mesophyllum... 2,4,5,8,9, 15, pis. 2, 3

guamensis, Dermatolithon.... .... 3,4,6,8,9,30, pi. 10

Jania- - -_____--_ 3,4,6,8,36, pi. 12

Melobesia ...... ...... - 3,4,6,9, SO, pi. 10

H 

Halimeda 2,5,6,37

sp 2,3,4,5,8,9, pi. 12

hanzawaii, Lithophyllum 17 

heterothallum, Lithothamnium. 28

Jania- -.- ....--- 2,6,31,36

guamensis ---------- -- 3,4,6,8,36, pi. 12

eetus.-. - 3,4,6,36

sp____.________.--_____-- 2,5,6

Joculator........ 31

K

kladosum, LUhophyllum. -.. 3,4,5,16, 21, 22

kotschyanum, Lithophyllum... -. 3,9,16,21, pi. 15

madagascariensis, Lithophyllum... ..... 21, pi. 14

subtilis, Lithophyllum- 21

typica, Lithophyllum 21

laccadivicum, Goniolithon........ .. . . . - 26

ladronicum, Lithothamnium.....----- ----- 5,12

laffittei, Mesophyllum- ...... --- 15

lauense, Archaeolithothamnium...- 2,4,5, JO, pi. 10 

lecroixi, Lithothamnium-..... 5, 12

lemoini, Lithophyllum...- - ---------------- 20

liberum, Archaeolithothamnium 5 

lichenoides, Lithothamnium----- 6

Lithophylleae----.--------------------------- 16

Lithophyllum 2,6,11,14, 16, 17,18,20,22,23,24,28 

albanense. 19,20

alifanenae 3,4,5,9,16, 17, pi. 3

aUernatum. - 3,4, 5,9,16, #0, pi. 5

aUernicellum. 3,4,5,8,9,16, 20, pi. 6

bamleri- 20

bonyense- ... 3, 4, 5,9,16,17, 19, pis. 4, 5 

craspedium...------------------------------ 24

expansum.....--.-- ---------- 6

fulangasum....------------- 17

glangeaudi - 3, 4, 5, 9, 16, W, pi. 6

hanzawaii....- -- 17

Uadosum . 3, 4, 5, 16, SI, 22

kotschyanum- . . 3, 9, 16, 21, pi. 15 

madagascariensis------------------- 21, pi. 14

aito-fiM 21

typica- . -.-----.----.--.------------- 21

lemoini---- 20

madagascarense.. ----...------------------ 21

maemongense - 3, 4, 5, 8, 16, 17, pi. 4 

megacrustum...... 6

meZoftesioides-------------------------------- 5

moluccense---- ---__------- 3,5,6,16, 20,21, 22

flabelliformis. . - 8, 22, pi. 13

pygamea-----... - . 9, 22, pi. 13

typica. .--------------.-.--.-----..--. 22

obliquum . 3, 4, 5, 9, 16, *8, pi. 4

oblongum ---------- ----- --------- 22

G39
G40 INDEX

Page 

Lithophyllum Continued

okamurai- -- 27 

ovatum-.---.--...-------- 5

platyphyllum-- ~___--______ 20 

prelichenoides-... ..... 3, 4, 5, 16, 17, 18, 19

premoluccense ------ -._ 20, 23

profundum....... -.__-._____-. 22

pseudoamphiroa .. 3, 4, 5, 8, 16, 88, pi. 7

quadrangulum- ---_.. 18,19, pi. 4

welschi-- ---- . 3, 4, 5, 9, 16, 18, pi. 4

racewms------------------------------------ 6

rovertoi----------------- .. ._-- 6

schlangeri- . ....------ 3, 4, 9, 16, 18, pi. 3

sphaeroides... -- - 20 

stefaninii... ___ ______________ 6 

thikombian....-------_____...______ 18

traceyi--.-------------- 3, 4, 5, 8, 9, 16, 88, 23, pi. 6

(Porolithori) craspedium-.. .. -_______ 24

sp. A------ . --...-... 2, 3, 5, 16, 18

sp. B ...... - . --, 3, 4, 5, 8, 16, 18, pi. 4

sp. C .- . 3, 4, 5, 9, 16, S3, pis. 6, 7 

sp. E-.--- .--- -..- 3, 4, 5, 9, 16, SO, pi. 5 

sp. F- -_ 3, 4, 5, 8, 16, S3, pi. 12

sp. G. -. - - 3, 4, 5, 9, 16, 18, pi. 4 

sp._ -- - __..- .._.. 4, 5

Lithoporetta.... __ ._____ 2, 88, 29, pi. 4

atlantica.. . .._...______ 28 

conjuncta. ----------__.... 28

melobesioides-.... --.. 2,3,4,5,6,28, S9, pis. 3, 4

(Melobesia) melobesioides- ------.. - 29

sp. A _ 3, 4, 6, 8, 89, pi. 10

(Lithoporetta) melobesioides, Mastophora -- 29 

melobesioides, Melobesia-... 29

L ithothamnieae.__________________ 10

Lithothamnion. (See Lithothamnium.)

Lithothamnium ... _____. 2, 6, 10, 11, 14, 16 

abrardi.... . ._- 5

aggregatum . . 2, 5, JJ 

alifanense _ __. 2, 4, 5, 9, 11, IS, pi. 1 

oroti - . - -.. 2,4,5,8,11, 13, pis. 1,2 

aucklandicum.----------------------------- 6

better!_ _________- ._______ 12 

bonyense--.---------.... __. 2, 4, 5, 8, JJ, pi. 1

bourcarti - -- . 2, 4, 5, 8, 11, 18, pi. 1 

crispatum...-... ..-- .. 2, 4, 5, 11, ^4

crispithallus.-------... ..__.--- -.. 2, 5, 11, 18

cymbicrustum..... ........___._____. 5

disarmonicum....------_--.-------.._------_ 5

engelhartii-__.... ___... ___.-- 6

fosliei.----..----------.....------...-------- 25

fumigatum..-..-.-..----------.-.._------- 5

funafutiense__. _ _. 2,5,6,11,^0 

heterothallum...-- - 28 

ladronicum...... .._______.._____ 5,12

lecroixi. ....... ._-. ____. 5,12

lichenoides---..... ...__.________ 6

madagascariense...... ___________- 6

maemongense.. ------__ 2,4,5,8,9,11, 18, pi. 1

marianae---- ----_-...__...-__ 2,5,11, 14

mirabile.... ..__________________ 5,14

moreti-.- .....--.- -__.._____.. 5

nanosporum.---...-__-___-____. 5 

onkodes---.....-..____________.. 23

peleense --------------- 2,4,5,8,11,18,13, pi. 2

saipanense- -- . __-.-____ 2,4,5,11, 13

subtile. --------------___________ 5

__- _. _-.___ 2,5,11,13

Page 

Lithothamnium Continued

tanapagense... . -- ---- 6

undulatum............ ....... 5

wattisium.._.___ . .- 5 

sp. A -- --- - 2,5,11,13

sp. F__ - 2,4,5,9,11,^, pi. 2

sp. a___ _ - .- 2,4,5,9,11, 13, pi. 1 

sp. H. ------_---.----------- 2,4,5,9,11, 14, pi. 2

sp. ______________________ 4

Lithotrix-......_____ __

lugeoni, Archaeolithothamnium .

M

madagascarense, Lithophyllum................... 21

madagascariense, Lithothamnium..... - - 6

madagascariensis, Lithophyllum kotschyanum- 0.7, pi. 14 

maemongense, Lithophyllum------- 3,4,5,8,16, 17, pi. 4

Lithothamnium -------- 2,4,5,8,9, 11,IS, pi. 1

marianae, Lithothamnium .. 2,5,11,14 

Mastophora (Lithoporella) melobesioides 29 

matansa, Corallina.....---------------------- 2,3,5,34

medioramus, Goniolithon.....-- 3,9,24,05,26, pis. 13,15

megacrustum, Lithophyllum----. .... 6

megasporum, Archaeolithothamnium..----..-.... 6

Melobesia--. ..........---------------------- 2,30

cuboides.....--------- --.. ----- 5

guamensis... . ... 3,4,6,9, SO, pi. 10 

(Lithoporella) melobesioides. -...--------... 29

(Melobesia) melobesioides, Lithoporella- -.- 29 

Melobesioideae--_..-- -----.-..-.. 2,9,27

melobesioides, Lithophyllum-...- - -- 5 

Lithoporella 2,3,4,5, 6,28,09, pis. 3,4 

Lithoporella (Melobesia) ------------- -- 29

Mastophora (Lithoporella)- --------....... 29

Melobesia (Lithoporella)... - --- 29 

Mesolithon.... --_ - - 27

Mesophyllum.-..._.__.___. _ 2,6, 14 

commune.-. ____ -------- 2,4,5,9,^4, Pi- 2

grande.. _______________ 2,4,5,8, 16, pi. 2 

guamense...... .......---- 2,4,5,8,9,^5, pis. 2,3

laffittei .._.... .. . 15 

pacificum..... _ 2,4,5, 16

savornini.__- .. - 2,4, 5, 16

sp. C.------- - - 2,4,5,8,^5, pi. 3

sp. D.-- - - 2,4,5,8,^5, pi. 3 

miocenicum, Goniolithon...-------- 3,4,5,8,24,06, pi. 8

mirabile, Lithothamnium-- --- 5,14

moluccense, Lithophyllum-.. -... 3,5,6,16,20, 81, ?2

flabelliformis, Lithophyllum ------ 8,22, pi. 13

pygmaea, Lithophyllum................ 9,22, pi. 13

typica, Lithophyllum- 22

moreti, Lithothamnium.. - 5 

myriosporum, Archaeolithothamnium--- ------- 5

N

nanosporum, Lithothamnium----------- 5

neuschelorum, Corallina. --- 3,4,6,35 

nitida, Dermatolithon ---------------- 2,3,5,6,30

O

obliquum, Lithophyllum- . 3, 4, 5, 9, 16, 18, pi. 4 

oblongum, Lithophyllum,- ... _. 22 

okamurai, Lithophyllum...-- - ---- 27 

onkodes, Lithothamnium__- ._-_. 23 

Porolithon-----._. . .--_.. 3, 6, S3 

oulianovi, Archaeolithothamnium.... --. 5 

ovatum, Lithophyllum- --.. 5

Page

pacifica, Cymopolia_____. 2, 3, 5, 8, 36, 37, pi. 12 

pacificum, Mesophyllum . 2,4, 5, 15 

peleense, Lithothamnium-- . 2, 4, 5, 8, 11, IS, 13, pi. 2 

Perforating algae_. __ 2, 4, 5 

platyphyllum, Lithophyllum. __ ____ 20 

Porolithon------ --.- 2,6, 16, #3

craspedium. _ __ _ . 3, 5, 6, S4

onkodes _ _-____________. 3, 6, 83

(Porolithon) craspedium, Lithophyllum.. .... 24

prefragilissima, Amphiroa - 3, 4, 6, 8, 9, 38, pi. 11 

prelichenoides, Lithophyllum ___.. 3,4,5,16,17,18,^9 

premoluccense, Lithophyllum,-................... 20, 23

prisca, Corallina- ---- . 2, 3, 5, 34

problematicum, Aethesolithon. 3, 4, 6, 8, 87, 28, pi. 9 

profundum, Lithophyllum- .. 22

pseudoamphiroa, Lithophyllum-.- 3, 4, 5, 8,16, 8i, pi. 7 

puntiense, Archaeolithothamnium--.. 2, 4, 5, 6, 10 

pygmaea, Lithophyllum moluccense --- 9, 22, pi. 13

Q

quadrangulum, Ltthophyllum..........-.-. 18,19, pi. 4

welschi, Lithophyllum . 3, 4, 5, 9, 16, 18, pi. 4

R 

racemus, Lithophyllum... _ -------- ... 6

regularis, Amphiroa__ . 3, 4, 6, 9, 33, 34, pi. 11 

reinboldi, Goniolithon ___- 3, 9, 24, S6, pis. 13, 15 

Rhodophyta____-_--_____ .... 1, 2, 9

Rotalia atjehensis___--------__ -. 4

rovertoi, Lithophyllum- ..... 6

S

saipanense, Archaeolithothamnium.--...... 2,5,10

Dermatolithon.-__ _ ____ 6, 30

Lithothamnium- __ ..__ . 2,4,5, 11, 13

savornini, Mesophyllum,- .. .. 2,4, 5, 15

schlangeri, Lithophyllum _. 3,4,9,16,^8, pi. 3

sphaeroides, Lithophyllum-...................... 20

stefaninii, Lithophyllum ----------------------- 6

Subterraniphyllum.-.........- . 27

subtile, Lithothamnium.......................... 5

subtilis, Lithophyllum kotschyanum.-... 21

T

tagpotchaense, Lithothamnium-.... . 2, 5, 11, 13

taiwanensis, Archaeolithothamnium .... 2, 4, 5, 10

tanapagense, Lithothamnium _....... . 6

tan-i, Amphiroa------_------ 3, 4, 6, 9, 33, pi. 11

thikombian, Lithophyllum-. - - - 18

traceyi, Lithophyllum. _ 3,4, 5,8, 9,16, **, 23, pi. 6

typica, Lithophyllum kotschyanum. .-.- 21

Lithophyllum moluccense .... ---- 22

U

undulatum, Lithothamnium.

verricosa, Amphiroa. ...... 3, 4, 6, 9, 33, pi. 11

vetus, Jama .' ' - 3, 4, 6, 36

W

wallisium, Lithothamnium----------------...... 5

welschi, Lithophyllum quadrangulum. 3,4,5,9,16, 18, pi. 4

yendoi, Lithophyllum.

O
PLATES 1-15
PLATE 1

FIGURES 1-3. Lithothamnium maemongense Johnson n. sp. (p. G12). Lower Miocene, Maemong Limestone Member of Umatac 

Formation.

1. Vertical section of a very thin crust, X 100, consisting mainly of hypothallus. Loc. D924 (li 6-33), holotype 

specimen A699.

2. Vertical section, X 50, showing the hypothallus, perithallus, and two conceptacle chambers. Loc. D899 (Fi 

6-7), specimen A698.

3. Vertical section showing two superimposed thalli, X 100; the upper one has a well-developed hypothallus and 

perithallus. Loc. D926 (li 6-36), specimen A700.

4. Lithothamnium cf. L. araii Ishijima (p. G13).

Vertical section of thallus, X 50. Lower Micoene, Maemong Limestone Member of Umatac Formation; loc. D914 

(Hi 10-1), specimen A702a.

5. Lithothamnium bourcarti Lemoine (p. G12).

A nearly vertical section, X 50, showing the thin thallus and two conceptacle chambers. Lower Miocene, Maemong Limestone Member of Umatac Formation; loc. D900 (Fj 2-4), specimen A697.

6. Lithothamnium bonyense Johnson n. sp. (p. Gil).

A vertical section, X 50, showing the tissue consisting mainly of hypothallic tissue, with six partly filled conceptacle 

chambers. Lower Miocene, Bonya Limestone; loc. D906 (Gj 1-1), holotype specimen A696.

7. Lithothamnium alifanense Johnson n. sp. (p. G12).

Specimen, X 50, showing a thin basal hypothallus and thick perithallus with suggestions of growth zones. Upper 

Miocene and Pliocene, Alifan Limestone; loc. D941 (Ts 16-6), holotype specimen A701.

8. Lithothamnium sp. G (p. G13).

A nearly vertical section, X 100, showing the hypothallus of curved rows of cells and the thicker regular perithallusLower Miocene, Maemong Limestone Member of Umatac Formation; loc. D926 (li 6-36), specimen A700.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G PLATE 1

MIOCENE LITHOTHAMNIUM
PLATE 2

FIGURE 1. Lithothamnium ct. L. peleense Lemoine (p. G12).

A vertical section, X 100, showing the hypothallus and perithallus. Lower Miocene, Maemong Limestone Member 

of Umatac Formation; loc. D914 (Hi 10-1), specimen A702b.

2. Lithothamnium cf. L. araii Ishijima (p. G13).

A nearly vertical section, X 50, showing the hypothallus and the thick perithallus with its well-defined growth zones. 

Lower Miocene, Maemong Limestone Member of Umatac Formation; loc. D921 (li 6-27), specimen A705.

3. Mesophyllum commune Lemoine (p. G14).

Tangential section of a branch, X 50. The tissue contains pronounced growth zones and four conceptacles with 

sporangia. Lower Miocene, Maemong Limestone Member of Umatac Formation; loc. D928 (li 6-38), specimen 

A708.

4. Lithothamnium sp. H (p G14.).

A vertical section, X 50. Upper Miocene and Pliocene, Alifan Limestone; loc. D936 (Ts 9-1), specimen A706.

5. Mesophyllum grande Johnson n. sp. (p. G15).

Longitudinal section, X 50, of a branch showing growth zones and large conceptacle chambers (the lower ones partly 

filled). Specimen badly recrystallized. Lower Miocene, Maemong Limestone Member of Umatac Formation; 

loc. D918 (li 6-8), holotype specimen A709.

6. Lithothamnium sp. F (p. G14).

Slightly oblique section, X 50. Lower Miocene, Maemong Limestone Member of Umatac Formation; loc. D926 

(li 6-36), specimen A707.

7. Mesophyllum guamense Johnson n. sp. (p. G15).

Fragment of a branch, X 50, showing structure of the tissue. Lower Miocene, Maemong Limestone Member of Umatac 

Formation; loc. D922 (li 6-28), specimen A711.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G PLATE 2

6 7 

MIOCENE LITHOTHAMNIUM AND MESOPHYLLUM
PLATE 3

FIGURE 1. Mesophyllum sp. C (p. G15).

A slightly oblique tangential section of a worn branch, X 50. Lower Miocene, Bonya Limestone; loc. D909 (G]

7-2), specimen A713. 

2. Lithophyllum schlangeri Johnson n. sp. (p. G18).

Vertical section, X 50, showing the well-developed hypothallus, the thin perithallus, and two conceptacles with 

sporangia. Lower Miocene, Maemong Limestone Member of Umatac Formation; loc. D927 (li 6-37), holotype 

specimen A710a. 

3-5. Lithophyllum alifanense Johnson n. sp. (p. G17).

Upper Miocene and Pliocene, Alifan Limestone.

3. Lithophyllum alifanense Johnson n. sp. and Lithoporella melobesioides Foslie (at top). Specimen slightly recrystallized, X 50. Loc. D936 (Ts 9-1); holotype specimen A715.

4. An oblique section, X 100, giving details of the tissue and two conceptacles with sporangia. Loc. D938 (Ts 

16-2), specimen A716.

5. Section of a young plant, X 50. Loc. D940 (Ts 16-5), specimen A718 

6, 7. Mesophyllum guamense Johnson n. sp. (p. G15).

Lower Miocene, Maemong Limestone Member of Umatac Formation.

6. Section of a branch, X 50, with strong lenticular growth zones. Loc. D911 (Hi 3-5), specimen A712.

7. An oblique section, X 50, of a fertile branch. Loc. D927 (li 6-37), holotype specimen A710a. 

8. Mesophyllum sp. D (p. G15).

Fragment of a branch, X 50. Lower Miocene, Maemong Limestone Member of Umatac Formation; loc. D920 

(li 6-26), specimen A714a.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G PLATE 3

MIOCENE MESOPHYLLUM AND LITHOPHYLLUM
PLATE 4

FIGTJBES 1-3. Lithophyllum maemongense Johnson n. sp. (p. G17).

Lower Miocene, Maemong Limestone Member of Umatac Formation.

1. Section of a typical crust, X 50, with distinct hypothallus and perithallus. Loc. D912 (Hi 6-1), specimen A720.

2. Several thalli with a Lithoporella between, X 30, conceptacle chamber in upper right. Loc. D891 (Ed 4-1), 

specimen A721.

3. Specimen, X 50, somewhat recrystallized with well-developed coaxial hypothallus, perithallus, and a conceptacle chamber. Loc. D919 (Li 6-25), holotype specimen A719. 

4, 6. Lithophyllum cf. L. obliquum Lemoine (p. G18).

Lower Miocene, Maemong Limestone Member of Umatac Formation.

4. Detail of hypothallus and perithallus, X 100, and a Lithoporella melobesioides Foslie below. Loc. D928 (li 6-38), 

specimen A708.

6. Section, X 50, with well-developed hypothallus and thick perithallus. Loc. D925 (li 6-34), specimen A723. 

5. Lithophyllum quadrangulum var. welschi Lemoine (p. G18). Specimen, X 100. Lower Miocene, Bonya Limestone;

Loc. D930 (Ih 14-1), specimen A724. 

7, 9. Lithophyllum sp. B (p. G18).

Lower Miocene, Maemong Limestone Member of Umatac Formation.

7. Section, X 40. Locality D910 (Hi 3-4), specimen A727. 

9. Detail of tissue, X 100. Loc. D900 (Fj 2-4), specimen A697. 

8. Lithophyllum bonyense Johnson n. sp. (p. G19).

Detail of tissue, X 100. Lower Miocene, Bonya Limestone, loc. D931 (Ih 14-2), specimen A730. 

10. Lithophyllum sp. G (p. G18).

Detail of tissue, X 100. Upper Miocene and Pliocene, Alifan Limestone; loc. D943 (Ts 16-12), specimen A728.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G PLATE 4

MIOCENE LITHOPHYLLUM
PLATE 5

FIGUBES 1, 2. Lithophyllum bonyense Johnson n. sp. (p. G19). 

Lower Miocene, Bonya Limestone.

1. Section, X 100, with large hypothallus and rather thin perithallus. Loc. D930 (Ih 14-1), holotype specimen 

A729.

2. Slightly oblique section of a thick crust, X 100. Locality D929 (Ih 5-6), specimen A731. 

3, 5, 6. Lithophyllum alternatum Johnson n. sp. (p. G20).

Upper Miocene and Pliocene, Alifan Limestone.

3. Detail from same specimen shown in fig. 6, X 100, showing the cells and alternate layers of long and short cells. 

Loc. D937 (Ts 16-1), specimen A734.

5. A tangential section, X 50, of a nearly complete branch with medullary hypothallus of alternate long and short 

cells and a marginal perithallus. Loc. D939 (Ts 16-3), holotype specimen A733.

6. A nearly vertical section, X 50. Loc. D937 (Ts 16-1), specimen A734. 

4. Lithophyllum sp. E (p. G20).

Fragment of a fertile crust, X 50. Upper Miocene and Pliocene, Barrigada Limestone; loc. D934 (Ov 7-3), 

specimen A732.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G PLATE 5

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MIOCENE LITHOPHYLLUM
PLATE 6

FIGURES 1, 2. Lithophyllum traceyi Johnson n. sp. (p. G20).

Lower Miocene, Maemong Limestone Member of Umatac Formation.

1. Longitudinal section of a branch, X 50, with medullary hypothallus, marginal perithallus, and a conceptacle 

chamber. Loc. D899 (Fi 6-7); holotype specimen A698.

2. Worn fragment of a branch, X 50. Loc. D925 (li 6-34), specimen A745. 

3, 4. Lithophyllum alternicellum Johnson n. sp. (p. G20). 

Lower Miocene, Bonya Limestone.

3. A slightly oblique nearly longitudinal section, X 50, of a fertile branch. Loc. D909 (Gj 7-2), holotype specimen 

A735.

4. Detail, X 100, of the tissue of a branch. Loc. D929 (Ih 5-6), specimen A736.

5. Lithophyllum sp. C (p. G23).

Slightly oblique tangential section of a branch, X 50. Lower Miocene, Maemong Limestone Member of Umatac 

Formation; loc. D927 (li 6-37), specimen A710b.

6. Lithophyllum aff. L. glangeaudi Lemoine (p. G21).

A slightly oblique longitudinal section, X 50. Upper Miocene and Pliocene, Alifan Limestone; loc. D936 (Ts 9-1), 

specimen A737.
GEOLOGICAL SURVEY

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MIOCENE LITHOPHYLLUM
PLATE 7

FIGURES 1-4. Ldthophyllum pseudoamphiroa Johnson n. sp. (p. G22).

Lower Miocene, Maemong Limestone Member of Umatac Formation.

1. Slightly oblique specimen, X40, showing young branches. Loc. D919 (li 6-25) specimen A743.

2. Branch arising from the basal hypothallus, X50. Loc. D900 (Fj 2-4), specimen A697.

3. Slightly oblique section, X 40. Loc. D919 (li 6-25), specimen A743.

4. Specimen showing details of branching, X 50. Loc. D900 (Fj 2-4), holotype specimen A697. 

5. Lithophyllum sp. C (p. G23).

Oblique section, X 100. Lower Miocene, Maemong Limestone Member of Umatac Formation; loc. D927 (li 6-37), 

specimen A710a.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G PLATE 7

MIOCENE LITHOPHYLLUM
PLATE 8

FIGUBES 1-3. Goniolithon miocenicum Johnson n. sp. (p. G26).

1. A basal section, X 100. Lower Miocene, Maemong Limestone Member of Umatac Formation; loc. D894 (Fd 

1-1), specimen A755.

2. A perpendicular section, X 100. Lower Miocene, Bonya Limestone; loc. D896 (Fi 3-4), specimen A754.

3. Perpendicular section, X 100, showing hypothallus, perithallic tissue with megacells, and numerous conceptacle 

chambers. Lower Miocene, Maemong Limestone Member of Umatac Formation; loc. D904 (Gi 1-1), holotype 

specimen A753. 

4. Goniolithon sp. C (p. G27).

Section, X. 50, showing tissue with several secondary patches of hypothallus developed as scar tissue. Upper Miocene 

and Pliocene, Alifan Limestone; loc. D936 (Ts 9-1), specimen A715.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G PLATE 8

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MIOCENE GONIOLITHON
PLATE 9

FIGURES 1-3. Aethesolithon problematicum Johnson n. sp. (p G27). 

Lower Miocene, Bonya Limestone.

1. A slightly oblique nearly longitudinal section of a branch, X 40, showing the medullary hypothallus with its 

growth zones and layers of large polygonal cells and the irregular marginal perithallus. Loc. D896 (Fi 3-4), 

holotype specimen A754.

2. Slightly oblique section, X 50, through side of a short branch showing perithallic tissue and conceptacles with 

sporangia. Loc. D895 (Fi 3-2), specimen A762.

3. Section of a branch, X 50. Loc. D898 (Fi 5-1), specimen A763. 

4, 5. Aethesolithon grandis Johnson n. sp. (p. G28).

Upper Miocene and Pliocene, Alifan Limestone.

4. A part, X 50, showing details of the medullary hypothallus and the transition from the hypothallus to the marginal 

perithallus. Loc. D940 (Ts 16-5), holotype specimen A764.

5. Margin of a mammillated crust, X 50, with conceptacles containing sporangia. Loc. D937 (Ts 16-1), specimen 

A765.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G PLATE 9

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MIOCENE AETHESOLITHON N. GEN.
PLATE 10

FIGTJKE 1. Dermatolithon sp. A (p. G30).

A nearly basal section, X 50. Lower Miocene, Maemong'Limestone Member of Umatac Formation; loc. D901 

(Fj 2-5), specimen A703.

2. Lithoporella sp. A (p. G29).

Section of a young plant, X 50. Lower Miocene, Maemong Limestone Member of Umatac Formation; loc. D908 

(Gj 4-4), specimen A768.

3. Dermatolithon sp. B (p. G30).

A slightly oblique section of a curved platy thallus, X 50. Upper Miocene and Pliocene, Alifan Limestone; loc.

D917 (Hn 7-3), specimen A704. 

4, 5. Dermatolithon guamensis Johnson n. sp. (p. G30).

Lower Miocene, Maemong Limestone Member of Umatac Formation.

4. A nearly basal section, X 50. Loc. D926 (li 6-36), specimen A700.

5. A nearly vertical slice, X 50 showing tissue and a conceptacle. Loc. D922 (li 6-28), holotype specimen A711. 

6. Melobesia quamensis Johnson n. sp. (p. G30).

Between two thalli of Archaeolithothamnium lauense Johnson and Ferris, X 100. Lower Miocene, Maemong

Limestone Member of Umatac Formation; loc. D923 (li 6-32), holotype specimen A722. 

7, 8. Aethesolithon grandis Johnson n. sp. (p. G28).

Upper Miocene and Pliocene, Alifan Limestone.

7. Detail of outer part of a crust, X 100, showing the irregular perithallic tissue and two conceptacles. Loc. D397 

(Ts 16-1), specimen A766.

8. Section of a long branch, X 25. Loc. D892 (Eh 3-3), specimen A767.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G PLATE 10

MIOCENE DERMATOLITHON, LITHOPORELLA, MELOBESIA, ARCHAEOLITHOTHAMNIUM, AND 

AETHESOLITHON; AND PLIOCENE AND PLEISTOCENE DERMATOLITHON
PLATE 11

FIGURE 1. Amphiroa cf. A. regularis Johnson and Ferris (p. G33).

A nearly complete segment, X 50. Upper Miocene and Pliocene, Alifan Limestone; loc. D944 (Tt 7-4),

specimen A769. 

2, 3, 5, 11. Amphiroa prefragilissima Lemoine (p. G32).

Upper Miocene and Pliocene, Alifan Limestone.

2. A broken segment, X 50. Loc. D937 (Ts 16-1), specimen A761.

3. A segment, X 40, with the medullary hypothallus but most of the marginal perithallus worn off. Loc.

D942 (Ts 16-9), specimen A747.

5. A nearly complete segment, X 40. Loc. D892 (Eh 3-3), specimen A767. 

11. A slightly oblique section of a segment, X 50. Loc. D893 (Eh 3-8), specimen A760. 

4. Corallina sp. A (p. G35).

Two segments and connecting node, X 40. Upper Miocene and Pliocene, Alifan limestone, loc. D916 (Hn

7-2), specimen A775. 

6, 12. Amphiroa tan-i Ishijima (p. G33).

Lower Miocene, Bonya Limestone.

6. A nearly complete segment, X 50. Loc. D930 (Ih 14-1), specimen A770. 

12. A segment, X 100. Loc. D931 (Ih 14-2), specimen A730.

7. Amphiroa cf. A. verricosa Ktitsing (p. G33).

A worn fragment, X 50. Upper Miocene and Pliocene, Barrigada Limestone; loc. D933 (Ov 7-2), specimen 

A771.

8. Amphiroa sp. D (p. G34).

An abraded fragment, X 50. Upper Miocene and Pliocene, Barrigada Limestone; loc. D935 (Rx 8-2),

specimen A774.

9, 10. Amphiroa anchiverricosa Johnson and Ferris (p. G32). 

Lower Miocene, Bonya Limestone.

9. An oblique section, X 40. Loc. D905 (Gi 2-7), specimen A742

10. Part of a segment, X 50, showing typical structure of tissue. Loc. D909 (Gj 7-2), specimen A713.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G PLATE 11

MIOCENE AMPHIROA AND CORALLINA
PLATE 12

FIGURES 1-3. Jania guamensis Johnson n. sp. (p. G36).

Lower Miocene, Maemong Limestone Member of Umatac Formation.

1. A nearly complete terminal segment, X 40. Loc. D913 (Hi 12-3), holotype specimen A777.

2. Pieces of two segments, X 50. Loc. D920 (li 6-26), specimen A714b.

3. Detail, X 100. Loc. D897 (Fd 4-1), specimen A778.

4. Halimeda sp. (p. G37).

A nearly complete segment, X 25. Lower Miocene, Maemong Limestone Member of Umatac Formation; loc. 

D907 (Gj 4-1), specimen A780.

5. Amphiroa sp. C (p. G33).

A worn fragment, X 100. Pleistocene fore-reef facies of Mariana Limestone; loc. D932 (Ji 1-1), specimen A773.

6. Corallina sp. A (p. G35).

Several segments, X 40, somewhat recrystallized. Upper Miocene and Pliocene, Alifan Limestone; loc. D915 

(Hn 7-1), specimen A776.

7. Lithophyllum sp. F (p. G23).

Section of a branch, X 100. Upper Miocene and Pliocene, Alifan Limestone; loc. D916 (Hn 7-2), specimen 

A748.

8. Halimeda sp. (p. G37).

A segment, X 25. Pliocene and Pleistocene, Mariana Limestone; loc. D945 (Uu 1-1), specimen A781. 

9, 10. Cymopolia cf. C. pacifica Johnson (p. G36).

Upper Eocene and Oligocene, Alutom Formation; loc. D902 (Fk 4-9), specimen A772.

9. A nearly horizontal section, X 25.

10. A slightly oblique vertical section, X 25.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G 

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EOCENE CYMOPOLIA; MIOCENE JANIA, HALIMEDA, CORALLINA, AND LITHOPHYLLUM,- 

PLIOCENE AND PLEISTOCENE HALIMEDA-AND PLEISTOCENE AMPHIROA
PLATE 13

FIGURE 1. Lithophyllum moluccensef. pygmaea Foslie (p. G21). On a piece of coral, X 1. Agana Reef (D946), specimens A741 

and-A782.

2. Goniolithon cf. G. fosliei (Heydrich) Foslie (p. G25). Coating a piece of dead coral, X 1. Agana Reef (D946), specimen 

A749.

3. Lithophyllum moluccense f. ftabelliformis Foslie (p. G21). Cocos Island Reef (D903), specimen A740, X 1-

4. 7. Goniolithon medioramus Johnson n. sp. (p. G25).

4. A small growth on coral, X 1. Agana Reef (D946), specimen A751. 

7. A larger colony, X 1. Agana Reef (D946), specimen A750.

5. 6. Goniolithon reinboldi Weber van Bosse and Foslie (p. G26).

5. Agana Reef (D946), specimen A757, X 1.

6. A colony coating coral, X 1. Numerous conceptacles give a postulate surface appearance to this and the specimen 

above. Agana Reef (D946), specimen A756.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G PLATE 13

3 7 

RECENT LITHOPHYLLUM AND GONIOLITHON
PLATE 14

FIGURES 1, 2. Lithophyllum kotschyanum Unger form Madagascariensis Foslie (p. G21).

A large specimen showing the wide platy branches characteristic of this growth form. Agana Reef (D946), 

specimen A738.

1. Side view, XI.

2. Top view, X 1.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G PLATE 14

RECENT LITHOPHYLLUM
PLATE 15

FIGURES 1, 2. Goniolithon medioramus Johnson n. sp. (p. G25). 

Agana Reef (D946), holotype specimen A752.

1. A nearly vertical section, X 50, showing structure of the tissue. Note the several patches of secondary hypothallus to right of center. They are scar tissue.

2. A slightly oblique vertical section, X 50. 

3. Lithophyllum kotschyanum (Unger) Foslie (p. G21).

Section of outer part of a branch, X 50, showing the marginal perithallus with conceptacles and part of the medullary hypothallus. Agana Reef (D946), specimen A739. 

4, 5. Goniolithon reinboldi Weber van Bosse and Foslie (p. G26). 

Agana Reef (D946).

4. Section of crust, X 50, showing the irregular tissue and numerous conceptacle chambers. Specimen A759.

5. Detail, X 100, of crust with basal hypothallus, the irregular perithallic tissue and a conceptacle. Specimen A758.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-G PLATE 15

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2 5 

RECENT GONIOLITHON AND LITHOPHYLLUM