Fossil Corals From 

Midway Atoll 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 680-G 
Fossil Corals From 

Midway Atoll 

By JOHN W. WELLS 

G E 0 L 0 G Y 0 F T H E M I D W A Y A R E A, H A W A I I A N I S L A N D S 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 680-G 

A description of corals 

from two cored holes through the 

reef cap of Midway atoll 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON 1982 
UNITED STATES DEPARTMENT OF THE INTERIOR 

JAMES G. WATT, Secretary 

GEOLOGICAL SURVEY 

Dallas L. Peck, Director 

Library of Congress Cataloging in Publication Data 

Wells, John West, 1907-

Fossil corals from Midway atoll. 

(Geology of the Midway Area, Hawaiian Islands) 

(Geological Survey professional paper ; 680-G) 

Bibliography: p. 

Supt. of Docs. no.: I 19.16:680-G 

1. Corals, Fossil. 2. Paleontology-Midway Islands. I. Title. II. Series. III. Series: Geological Survey professional 

paper ; 680-G. 

QE778.W43 563'.6'099699 81-607875 AACR2 

For sale by the Distribution Branch, U.S. Geological Survey, 

604 South Pickett Street, Alexandria, VA 22304 
CONTENTS 

Page 

Abstract __________________________________________________ ------------------------------------------- G 1 

Introduction ______________________________________________ ------------------------------------------- 1 

Acknowledgments _______________________________________________ ------------------------------- 1 

Living coral fauna of the Hawaiian Archipelago------------------------------------------------- 1 

Post-Miocene fossil corals-------------------------------------------------------------------------- 1 

Miocene corals _____________________________________________________________ ------------------------- 1 

Systematic descriptions ---------------------------------------------------------------------------- 3 

References cited __________________________________________ ------------------------------------------- 7 

ILLUSTRATIONS 

[Plates follow index) 

PLATES 1-3. Miocene corals 

1. Stylophora 

2. Seriatopora, Pocillopora, Acropora, Plesiastrea 

3. Favia, Favites, Galaxea 

Page 

FIGURE 1. Map of Midway atoll, showing location of drill holes ....................................................................................... . G2 

2. Stratigraphic distribution of 3 fossil reef corals from Midway drill holes ................................................................ . 

TABLE 

Page 

TABLE 1. Living shallow-water corals of the Hawaiian Islands and fossil corals from Midway_ ................................................. . G2 

l\Ietric unit 

millimeter (mm) meter (m) 

kilometer ( km) 

Rouare meter (m2) 

square kilometer ( km2) 

hectare ( ha) 

cubic centimeter ( cm3) 

liter (L) 

cubic meter (m3 ) 

cubic meter cubic hectometer (hma) 

liter 

liter 

liter 

cubic meter 

cubic meter 

gram (g) 

gram 

metric tons (t) 

metric tons 

kilogram per square centimeter (kg/cm2) kilogram per square 

centimeter 

cubic meter per second 

(m3/s) 

CONVERSION FACTORS 

Inch·l'OUJHl equivalent l\Ietric unit Inch-Pound equivalent 

Length Specific combinations-Continued 

O.O:·HlX7 inch (in) 

3.28 feet (ft) 

.62 mile (mi) 

Area 

10.76 

.386 

2.47 

Volume 

0.061 

61.03 

35.:n 

.00081 

=810.7 

2.113 

1.06 

.26 

.00026 

6.290 

Weight 

O.OX5 

.0022 

1.102 

0.9842 

square feet (ft2) 

square mile (mi2) acres 

cubic inch (ina) 

cubic inches 

cubic feet ( fta) 

acre-foot (acre-ft) 

acre-feet 

pints (pt) 

quarts (qt) gallon (gal) 

million gallons (l\fgal or 106 gal) barrels (bbl) (1 bbl=42 gal) 

ounce, avoirdupois (oz anlp) 

pound, avoirdupois (lb avdp) 

tons, short (2,000 lb) 

ton, long (2,240 lb) 

Specific combinations 

0.96 

.98 

3G.3 

atmosphere (atm) 

bar (0.9869 atm) 

cubic feet per second ( fta;s) 

liter per second (L/s) 

cubic meter per second 

per square kilometer 

[ ( m3 /s) jkm2 ] 

meter per day (m/d) 

meter per kilometer 

(m/km) 

kilometer per hour 

(km/h) 

meter per second (m/s) 

meter squared ller day (m2jd) 

cubic meter per second 

(ma;s) 

cuhie meter per minute 

(ma;min) 

litPr per second (L/s) 

liter per second per meter [ (L/s)/m] 

kilometer per hour 

(km/h) 

meter Iler second ( m/s) 

gram J)er cubic 

centimeter (g/cma) 

gram per square 

centimeter (g/cm2) 

gram per square 

centimeter 

degree Celsius (°C) 

degrees Celsius 

(temperature) 

.0353 

91.47 

3.28 

5.28 

.9113 

3.28 

10.764 

22.826 

=264.2 

Hi.85 

4.83 

.62 

2.2::17 

62.4::1 

2.048 

cubic foot per second 

cubic feet J)er second per 

square mile [ (ft3/s)/ml2 ] 

feet per day (hydraulic 

conductivity) (ft/d) 

feet per mile ( ft/mi) 

foot per second (ft/s) 

feet per second 

feet squared per day (ft2/d) 

(transmissivity) 

million gallons per day 

(Mgal/d) 

gallons per minute (gal/min) 

gallons per minute 

gallons per minute per foot 

[(gal/min) /ft] 

mile per hour (mi/h) 

miles per hour 

pounds per cubic foot (lb/fta) 

pounds per square foot (lb/ft2) 

.0142 pound per square inch (lb/in2) 

Temperature 

1.8 degrees Fahrenheit (°F) 

= [ ( 1. 8 X •c) +32] degrees Fahrenheit 

III 

GEOLOGY OF THE MIDWAY AREA, HAWAIIAN ISLANDS 

FOSSIL CORALS FROM MIDWAY ATOLL 

By jOHN W. WELLS 

ABSTRACT 

Fossil corals were recovered from the cores and cuttings of the two 

drill holes made on Midway atoll in 1965. Reef-building scleractinian 

corals were relatively continuous from near the surface to a depth of 

1,143 ft. Above 494ft, six species representing five genera were recognized, all identical with the living Hawaiian reef fauna; the age range 

was Pliocene to Holocene. At and below 494 ft was a poorly preserved 

surface reef fauna of Miocene age, represented by 10 genera and 13 

species; this fauna was unlike that of similar age found in the drill 

holes at Bikini and Enewetak (formerly Eniwetok). 

INTRODUCTION 

In two previous reports (Wells 1954b, 1964), the 

writer described fossil corals recovered from drill holes 

on Bikini and Enewetak (formerly Eniwetok) Atolls. At 

Bikini, two coral zones were recognized: (1) PliocenePleistocene from the surface to a depth of about 700 ft 

and (2) middle and upper Miocene from 725 to 1,100 ft. 

At Enewetak, from the surface to 620 ft, reef corals 

were scarce and poorly preserved; no forms characteristic of Pliocene or Pleistocene were found between Miocene and Holocene assemblages. Below 620ft, a Miocene 

assemblage was found, extending to at least 3,100 ft. 

Below this, an Eocene fauna was recovered from 4,078 to 

4,100 ft. 

At Midway atoll, two deep holes were drilled in 1965 

(Ladd and others, 1970). From the hole on Sand Island 

(fig. 1), drilled to the basalt at 568 ft, 11 core samples 

from depths of 13 to 331ft contained well-preserved reef 

corals, all belonging to genera and species still living at 

Midway and the main Hawaiian Islands. No corals were 

found in samples from 331 to 501ft. The deeper hole on 

the reef, opposite Sand Island, was drilled to 1,564 ft 

into the basalt basement (see Ladd and others, 1970). 

Core recovery was high, and corals were found in 63 

samples from 70 to 1,143 ft. Forty-nine of these were in 

the Miocene from 494 to 1,143 ft. Above 494 ft in the 

post-Miocene, preservation was good except for a few 

recrystallized remains. In the Miocene section, preservation was mainly as empty or partly empty molds of 

fragments of colonial hermatypes. 

ACKNOWLEDGMENTS 

Warren Blow of the Smithsonian Institution aided in 

the preparation of the material. Many of the photographs were prepared by Robert H. McKinney and 

Haruo E. Mochizuki of the U.S. Geological Survey. 

LIVING CORAL FAUNA OF THE 

HAW AllAN ARCHIPELAGO 

During the drilling operations at Midway, corals living on the reefs at Midway and Kure were collected by 

H.S. Ladd; collections were also made in 1968 and 1969 

by Dana (1971). These collections were studied by the 

writer in connection with the fossils recovered from the 

Midway drill holes. Table 1 tabulates (1) the living 

shallow-water (less than 120 ft) hermatypic corals in 

the main Hawaiian Islands, Midway, and Kure and (2) 

post-Miocene and Miocene fossil corals on Midway. 

Most of the living forms are very widespread tropical 

Pacific species; only a handful of apparently endemic 

forms was found, including Cyphastrea ocellina, Montipora jlabellata, Porites duerdeni, Psammocora brighami, and P. verrilli. At Midway and Kure, some 1,000 

miles northwest of the main Hawaiian group, only 16 of 

the 33 recorded species from Hawaii have been found, a 

not unexpected diversity attenuation. 

POST-MIOCENE FOSSIL CORALS 

The six species found in samples younger than the 

Miocene (fig. 2) from the Sand Island and reef holes are 

all shallow-water reef types living today in the 

Hawaiian Archipelago, with the exception of Leptoseris 

sp. cf. L. incrustans, which has not yet been definitely 

recorded from localities nearer than the Marshall Islands, although other species of Leptoseris occur in the 

main Hawaiian Islands at depths belo:w about 120 ft 

(Vaughan 1907). Notably lacking is Stylophora, relatively abundant in the Miocene section of the Midway 

reef hole, as well as Favia, Favites, Plesiastrea, and 

Galaxea. On the other hand, Acropora, which occurs in 

the Midway Miocene and is living in Hawaii, was not 

found in the post-Miocene section. No evidence as to the 

age-Pliocene or Pleistocene-is afforded by the meager post-Miocene coral assemblage. 

MIOCENE CORALS 

The Miocene coral assemblage (table 1; fig. 2) bears 

little resemblance to that found in the Bikini and Enewetak drill holes (Wells 1954b, 1964) or to that in the 

Miocene of Borneo, Java, and Palau. This Midway 

Miocene assemblage lacks such characteristic species 

as Seriatopora ornata, S. delicatula, S. micrommata, 

G1 
G2 FOSSIL CORALS FROM MIDWAY ATOLL 

TABLE 1-Living shallow-water corals of the Hawaiian Islands and 

fossil corals from Midway 

Living Corals Fossil Corals 

PostSpecies Holocene Miocene Miocene 

Hawaii Midway Kure Midway 

Acropora cytherea (Dana) ________ X 

humilis (Dana) ________________ X 

valida (Dana) _________________ X 

Alveopora verrilliana Dana _______ X 

Coscinaraea sp. -------------------- X 

Leptastrea bottae (M.E. & H.) _____ X 

Montipora dilatata Studer ________ X 

jlabellata Vaughan ____________ X 

patula Verrill ----------------- X 

Porites brighami Vaughan ________ X 

duerdeni Vaughan ____________ X 

lanuginosa Studer ____________ X 

pukoensis Vaughan ___________ X 

Psammocora brighami Vaughan __ X 

verrillli Vaughan _____________ X 

Montipora verrilli Vaughan _______ X X X 

venosa (Ehrenberg)_ __________ X X X 

Fungia scutaria Lamarck _________ X X X 

Leptastrea purpurea (Dana) ______ X X X 

Montipora verrucosa (Lamarck) __ X X X 

Pavona varians Verrill_ ___________ X X X 

Pocillopora damicornis 

(Linnaeus) ------------------ X X X 

meandrina Dana ______________ X X X 

Porites compressa Dana ___________ X X X 

evermanni Vaughan __________ X X X 

(Synaraea) hawaiiensis 

Vaughan --------------- X X X 

Psammocora stellata Verrill ______ X X X 

Cyphastrea ocellina (Dana) _______ X X X X 

Pavona clavus Dana _______________ X X X X 

Pocillopora ligulata Dana _________ X X X X 

Porites lobata Dana _______________ X X X X 

Pavona maldivensis (Gardiner) __ X X X 

Montipora tuberculosa 

(Lamarck) ___________________ X 

Leptoseris cf. incrustans 

(Quelch)--------------------- X 

Acropora sp. _______________________ X 

Favia sp. A,B,C ____________________ X 

Favites cf. chinensis (Verrill) ____ X 

Galaxea haligena Felix ____________ X 

Pocillopora cf. hemprichi 

Ehrenberg ------------------ X 

Porites sp. A,B,C __________________ X 

Stylophora gemmans Gerth _______ X 

pistillata (Esper) ------------ X 

Seriatopora cf. hystrix Dana ---- X 

Plesiastrea cf. curta (Dana) ----- X 

Dictyaraea micrantha, and Alveopora polyacantha. The 

relative abundance of Stylophora, Pocillopora, and 

Porites, genera lacking or uncommon in the Bikini and 

Enewetak Miocene, suggests a reef-fiat rather than a 

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CONTOURS IN FATHOMS 

FIGURE 1.-Map of Midway atoll, showing location of drill holes. S, 

Sand Island hole; R, reef hole. 

lagoonal environment. Only one species, Stylophora 

gemmans, relating to the Miocene faunas of Lau, Fiji, 

and Eua, Tonga (Hoffmeister, 1945), is found at Midway. 

Two Midway species, S. gem mans Gerth (Miocene, 

Borneo) and Galaxea haligena Felix (Miocene, Borneo; 

Pliocene, Java), were originally described from 

Indonesia. 

Stylophora, Seriatopora, Favia, Favites, and Galaxea 

are genera absent from the post-Miocene and Holocene 

of the Hawaiian Archipelago and the Far Eastern 

Pacific; their presence in the Midway Miocene indicates 

a much broader distribution, at that time, of these common tropical Pacific genera. 

SYSTEMATIC DESCRIPTIONS 

Sample localities are followed by numbers indicating 

depths in feet in the Sand Island or reef holes; for example, Sand Island hole 65-66, 331; reef hole 304-312, 361. 

Genus STYLOPHORA Schweigger 1819 

Stylophora pistillata (Esper 1795) 

Plate 1, figures 1-6 

Stylophora pistillata Veron and Pichon 1976, p. 66, figs. 131-150 

(synonymy) 

Two growth forms ( ecomorphs ), pistillata and mordax, of this highly polymorphic species as revised by 

Veron and Pichon occur in 34 of the 45 core samples 

from depths of 590 to 1,061 ft. Ecomorph pistillata, 

which has branches 8-15 mm thick, is much less 
Hermatypic species Post-Miocene Miocene 

100 200 300 400 500 600 700 800 900 1,000 1,100 

1 l I I I J I J I J 1 

Pavona clavus Dana -

maldivensis (Gardiner) - - -

Pocillopora ligulata Dana -

Porites lobata Dana -----

Cyphastrea ocellina (Dana) - -

Leptoseris ct. incrustans (Quelch) -

- Galaxea cf. heligena Felix 

-- Pocil/opora cf. hemprichi Ehrenberg 

- Favia sp. C. 

- - -- - Stylophora pistiflata (Esper) 

pistil/ata mordax form --- - -- -

Porites sp. A - - -

Stylophora gemmans Gerth - -

Plesiastrea cf. curta (Dana) --

Porites sp. B -

Acropora sp. -

Favia sp. A - -

sp. B -

Seriatopora ct. hystrix Dana -

Favites sp. ct. F. chinensis (Verrill) - - -

J I I I I I I l I I I 

FIGURE 2.-Stratigraphic distribution of fossil reef corals from Midway drill holes. S, Sand Island hole; R, reef hole. 

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G4 GEOLOGY OF THE MIDWAY AREA, HAWAIIAN ISLANDS 

common (8 samples) than is the mordax form (26 samples) which has compressed to fiabellate branches 10-15 

mm thick and as much as at least 50 mm wide. 

Stylophora pistillata and ecomorph mordax are 

widely distributed today from the Red Sea through the 

Indian Ocean and on through the Pacific to the Tuamotus but are not yet recorded from the Marquesas, 

Johnston Island, Hawaii, or the extreme eastern Pacific. 

Fossil specimens, however, of S. pistillata (ecomorph 

mordax), together with Pocillopora, Porites, and Plesiastrea sp. cf. P. curta, were dredged from a guyot on the 

Nasca Ridge at a depth of 950 m (Fisher, 1958, p. 22-23); 

from another guyot at depths of 210 to 227 m, Stylophora, Pocillopora, Porites, and Leptoseris were reported by Durham (in Allison and others, 1967, p. 4). 

The ages of these two fossil assemblages are quite uncertain, but they are not earlier than Miocene (Holden, 

1967, p. 3). There are many records of S. pistillata from 

the Pliocene and Pleistocene from the Red Sea east into 

Indonesia, and in the Miocene from East Africa east 

through Indonesia into the western Pacific (Bikini, Enewetak) and the north-central Pacific (Midway). Other 

species described from the Miocene of India and Indonesia probably are within the range of S. pistillata, 

because the species criteria commonly used, such as 

calice dimensions, hoods or their absence, variation in 

septal details, and coenosteal ornamentation, are all 

highly variable even within a single colony (see Veron 

and Pichon's (1976) figures). 

Age.-Miocene, Midway. 

Locality .-Midway, reef hole, pistillata form: 590-595, 

961-962, 963-964, 990-993, 993-994, 1,057-1061, 1,061-

1,066; mordax form: 595-600, 613, 619, 627-629, 631-636, 

638, 651, 657, 662, 671-676, 678-679, 684, 701, 746, 751, 

754, 781, 783, 826-831, 831-832, 836-837, 842, 879-880, 

882-883, 901-906, 970-971. 

Stylophol'a gemmans Gel'lh 1923 

Plate 1, figures 7-9 

Stylophora gemmans Gerth 1923, p. 98, pl. 7, fig. 9 

?Stylophora verrucosa Gerth 1923, p. 97, pl. 7, figs. 7, 8 

Hoffmeister 1945, p. 300, pl. 11, figs. A, B 

Three samples from the reef hole at 659, 671-676, and 

970ft show external molds of what appear to have been 

encrusting or laminate coralla, which have scattered 

verrucaelike projections bearing calices; these features 

agree with those of the fragment from the Miocene of 

Borneo described as S. gem mans by Gerth. The calices 

range in diameter from 0.4 to 0.6 mm, flush with a 

slightly raised sharp rim or with a raised rounded rim, 

and lacking hoods. A directive pair of the six primary 

septa joins the styliform columella. A second cycle of 

short septa is found in some calices. Intercalicular coenosteum surface evenly spinulose. 

The S. verrucosa of Gerth (1923) and the specimen 

later identified by Hoffmeister (1945) from the Miocene 

of Lau (Fiji) were broken branches bearing pocilloporoid verrucae, and except for the apparent 

difference in growth form could well be the same as S. 

gemmans. A verrucate Stylophora, S. monticulosa, described by Hoffmeister (Vaughan and Hoffmeister, 

1925) from the Miocene of the Dominican Republic, has 

a branching habit and larger calices (0.5-0.75 mm). 

Scheer (1964, 1967) has named two verrucate species, S. 

wellsi and S. hassi, from the Red Sea, that have even 

larger calices (0.8-1.2 mm), but in these, the stubby 

verrucae are irregularly developed, some of them giving 

rise to short branchlets. These Holocene forms may be 

only stunted colonies of S. subseriata (Ehrenberg) in 

which the branches commonly have similar projections, 

the more distal of which develop into branchlets. 

Age.-Miocene, Midway; Borneo; Lau, Fiji. 

Locality .-Midway, reef hole: 659, 671-676, 970-971. 

Genus SERIATOPORA Lamal'ck 1816 

Sel'iatopol'a sp. cf. S. hysll'ix Dana 1846 

Plate 2, figures 1, 2 

Seriatopora hystrix Veron and Pichon 1976, p. 58, figs. 91-118 

(synonymy) 

Specimens of broken branches, all external molds, 

were found between 946 and 993 ft in the reef hole, 

associated with Stylophora. The branches are 2-5 mm in 

diameter and have calices 0.6-0.8 mm in size. Calices 

slightly protuberant with distal margins more elevated 

than the proximals. Coenosteum finely and evenly granulated, subcostate near calicular margins. Six septa, the 

directive pair being aligned with the axis of the branch. 

The fragments are not sufficiently well preserved to 

make a reasonably certain specific determination, but 

they certainly do not represent either of the two distinctive Miocene species, S. micrommata and S. ornata, 

which were described by Felix (1921) from Borneo and 

recognized again in Borneo by Umbgrove (1929) and, 

more recently, by Wells (1954a, 1964) in Miocene samples from the Bikini and Enewetak drill cores. A third 

Miocene species, S. delicatula Felix (1921; Umbgrove 

1929), is probably S. hystrix, a living Indo-Pacific polymorphic form elaborately illustrated by Veron and 

Pichon (1976), with which the Midway fragments are 

here compared. 

Age. -Miocene, Midway. 

Locality. -Midway, reef hole: 946-951 (with Favites, 

Porites, and Stylophora); 958-959, 961-962 (with 

Stylophora); 963-964 (with Stylophora); 990-993 (with 

Stylophora). 

Genus POCILLOPORA Lamal'ck 1816 

Pocillopol'a ligulata Dana 1846 

Pocillopora ligulata Dana 1846, p. 529, pl. 50, figs. 3, 3a 

Vaughan 1907, p. 94, pl.14, figs.1, 1a; pl. 17, figs. 2, 

2a; pls. 18-21 

Wells 1954a, p. 413, pl. 99, figs. 3, 4 

Several algal-crusted, broken stout branches of this 

typical living Hawaiian species was found at 79 and 
FOSSIL CORALS FROM MIDWAY ATOLL G5 

81 ft in the Midway reef hole. On one fragment, the 

calicular surface is well preserved and shows the characteristic septa and columella. 

Age. -Pleistocene and Holocene, Midway. 

Locality. -Midway, reef hole: 79, 80-81. 

Poc:illopora sp. c:f. P. hempric:hi Ehrenberg 1834 

Plate 2, figures 3, 4 

Pocillopora hemprichi Ehrenberg 1834, p. 128 

Milne Edwards and Haime 1860, p. 304 

Klunzinger 1879, p. 29, pl. 7, fig. 1; pl. 8, fig. 13 

Pieces of stout branches that have small appressed 

verrucae belong to the species group having closely set 

deep calices lacking septa and columella and marked by 

finely spinulose coenosteum. These specimens do not 

pertain to the few Pocillopora species reported from the 

Miocene of the Indo-Pacific (P. eydouxi, P. jenkinsi, P. 

ligulata, and P. solida ), all forms having well-developed 

septa and columella. Comparison with Holocene species 

lacking septa and columella is difficult, but among the 

25 or more nominal aseptate forms, only one, P. hemprichi from the Red Sea, appears to be related to the 

Midway fossils by its robust, often flattened or 

subflabellate branches having appressed verrucae. 

Age.-Miocene, Midway. 

Locality.-Midway, reef hole: 595-600, 627-629, 631-

63~ 63~ 641, 661-66~ 678-679, 68~ 809-81~ 831-832. 

Ac:ropora Oken 1815 

Ac:ropora sp. 

Plate 2, figures 5, 6 

Two small external molds of calicular surfaces cannot 

be identified further, although differences in corallite 

size suggest two different species. 

Acropora is known to be still living in Hawaiian waters (Maragos, 1977). 

Age. -Miocene, Midway; Pleistocene and Holocene, 

Hawaii. 

Locality.-Midway, reef hole: 901-906, 946-951. 

Genus PAVONA Lamarc:k 1801 

Pavona c:lavus Dana 1846 

Pnvona clavus Dana 1846, p. 332, pl. 24, fig. 4 

Wells 1954a, p. 441, pl. 152, fig. 1, 2 (synonymy) 

One specimen, part of a massive corallum, is placed in 

this variable and widespread Indo-Pacific reef species. 

Age.-Pleistocene, Midway; Pliocene and Pleistocene, 

Indonesia, New Caledonia; subfossil and Holocene, 

Indo-Pacific. 

Locality.-Midway, Sand Island hole: 78-83; living at 

Midway. 

Pavona maldivensis (Gardiner 1905) 

Siderastrea maldivensis Gardiner 1905, p. 935, pl. 89, fig. 3 

Pavona maldivensis Matthai 1948, p. 182, pl. 6, fig. 20; pl. 12, fig. 47 

Pavonn (Pseudocolumnastraea) pollicata Wells 1954a, p. 483, pl. 153, 

figs. 1-3 

Dana 1970, p. 82 

Leptoseris incrustans Dana 1970 (non Quelch) p. 82 

?Heliastrea digitata Duncan 1880, p. 89, pl. 21, figs. 7, 8 

A variant of this species occurs on the living reefs at 

Midway and as fossil in the upper part of the drill holes. 

The calicular centers on the thin laminar expansions 

are strongly individualized, often closely packed together, 2-2.5 mm in overall diameter, elevated to 3.5 

mm, erect or inclined, or distorted by intratentacular 

increase, with 20-45 alternating septa. From the laminar sheets arise pollicate elevations bearing smaller, 

less elevated calices with 20-30 septa. 

Age. -Post-Miocene and Holocene, Midway; Holocene, Indo-Pacific (Madagascar east to Tahiti and Tuamotus, Hawaii). 

Locality. -Midway, Sand Island hole: 65-66, 331; reef 

hole: 304-312, 361. 

Genus LEPTOSERIS Milne Edwards and Baime 1849 

Leptoseris sp. c:f. L. inc:rustans (Quelc:h 1886) 

Leptoseris incrustans Wells 1954a, p. 444, pl. 154, figs. 5-7 (synonymy) 

One fragment, very poorly preserved, is referred to 

this Pacific pavonid, living normally at 15-80 m, but not 

known certainly to be still living in Hawaiian waters. 

The specimen from Nero Bank erroneously identified by 

the writer in Dana (1971), is Pavona maldivensis. 

Age. -Pliocene and Pleistocene, Midway. 

Locality. -Midway, reef hole: 243-248. 

Genus PORITES Link 1807 

Porites lobata Dana 1846 

Porites lobntn Dana 1846, p. 562, pl. 55, fig. 1 

Vaughan 1907, p. 196, pl. 81, figs. 1, 2; pls. 82, 83, 84, 

figs. 1, 2; pl. 85, fig. 1. 

This widespread Indo-Pacific species is common in 

the Midway core samples from 70 to 185 ft in various 

states of preservation. It has not been recorded from 

reef deposits older than subrecent, mainly because of 

the difficulty in determining Porites species when wellpreserved calicular surfaces are lacking. 

Age. -Post-Miocene and Holocene, Midway. 

Locality. -Midway, Sand Island hole: 113-118, 

141-142,161, 180-185;reefhole:70,87,103,111,129, 134, 

145-146, 154. 

Porites sp. A 

Fragments of a massive corallum were found in 

several core samples. Cut surfaces and badly worn calices show corallites 0.75-1.25 mm in diameter and having 

12 septa, but further details cannot be seen well enough 

to allow closer identification. 

Age. -Miocene, Midway. 

Locality. -Midway, reef hole: 613, 755, 879-880, 

1,067-1,069, 1,1,~0-1,1~9, 1,142..,1,143. 

Porites sp. B 

Molds in chalky limestone are remnants of a Porites 

that have fingerlike branches 1-1.5 em in diameter, but 

no calices are preserved. 

Age.-Miocene, Midway. 

Locality.-Midway reef hole: 779, 782-783. 
G6 GEOLOGY OF THE MIDWAY AREA, HAWAIIAN ISLANDS 

Genus FAVIA Oken 1815 

Recent species of this widespread Indo-Pacific genus 

are difficult to discriminate because of broad individual 

variation; fossil specimens are even more troublesome. 

Of the 6 samples in the Midway cores, 3 are external 

molds of a small group of calices, 1 shows only internal 

structures in section, and 2 are recrystallized fragments 

having moderately preserved calices. None of these 

specimens can be referred to any living or fossil species 

with any degree of certainty and are here placed in 

three groups: 

Favia sp. A 

Plate 3, figure 1 

Three external molds show slightly elevated calices 

8-10 mm in diameter, separated 3-5 mm, united by 

equal subspinose costae corresponding to all septa. 

Three cycles of stout septa, equal except in dividing 

calices. Details of septal margins and columella lacking. 

The few characters of the corallum that are preserved 

are suggestive of the grouping of recent forms referred 

to as the "Favia am~icorum complex" by Veron and 

Pichon (1977, p. 32, figs. 37 -44). 

Age. -Miocene, Midway. 

Locality. -Midway, reef hole: 901-906, 923-924, 

1,061-1,066 (with Stylophora and Acropora). 

Favia sp. B 

Plate 3, figure 2 

Two recrystallized fragments that have moderately 

well preserved calices are comparable with F. lizardensis, a new species from the Great Barrier Reefs, 

described recently by Veron and Pichon (1977). 

Age. -Miocene, Midway. 

Locality. -Midway, reef hole: 915-916. 

Favia sp. C 

Plate 3, figure 4 

A poorly preserved transverse section of a fragmentary corallum shows corallites 8-11 mm in diameter, 

separated by 1-2 mm and united by costae. Septa mostly 

16 in number, arranged 8/8, the first 8 with thickened 

inner ends extending to the axis where they join a very 

weak columella. The large size of the corallites and 

small number of septa are a combination uncommon in 

Favia, and a new species may be involved, but it will not 

be named until data on the nature of the calicular surface are found. 

Age. -Miocene, Midway. 

Locality. -Midway, reef hole: 590-595. 

Genus FAVITES Link 1807 

Favites sp. ef. F. ehinensis (Verrill 1866) 

Plate 3, figure 3 

Favites chinensis Veron and Pichon 1977, p. 53, figs. 83-88 (synonymy) 

Five external molds represent fragments having 2-4 

small polygonal calices 8-10 mm in diameter with 30-40 

septa. The molds are so poor that details of the septa 

and other structures cannot be determined. The only 

comparable species on the basis of gross features seems 

to be F. chinensis, in which Veron and Pichon absorbed 

two other Holocene forms: Prionastraea acuticollis 

Ortmann 1889 and F. yamanarii Y abe and Sugiyama 

1936. Two fossil species, Prionastraea dubia Reuss 1867 

from the Miocene of Java, and F. borneensis Gerth 1921 

from the Pliocene of Borneo and Nias probably belong 

here. 

Age. -Miocene, Midway. 

Locality. -Midway, reef hole: 915-916 (with Favia sp. 

B), 940-951 (with Porites), 993-994 (with Stylophora). 

Genus PLESIASTREA Milne Edwards and Haime 1848 

Plesiastrea sp. ef. P. curta (Dana 1846) 

Plate 2, figure 7 

Mantastraea curta Chevalier 1971, p. 278, pl. 9, fig. 4, pl. 33, figs. 5, 6; 

' pl. 34, fig. 1; pls. 35, 36 (synonymy) 

Veron and Pichon 1977, p. 137, figs. 257-263 

(synonymy) 

Specimens from five core samples from depths of 754 

to 789ft are most similar to the Holocene P. curta of the 

tropical Pacific. Preservation is poor; most of the original skeletal tissues have been dissolved, leaving only 

coarse molds that have no external details. Corallites 

range from 4 to 5 mm in diameter and have thick walls 

linked by subtabular dissepiments. Septa are thin and 

are arranged 18/18 to 20/20, the first 18 or 20 extending 

to a trabecular columella, the remaining 18 or 20 very 

short, equal, and stout. These characters are like those 

of Holocene P. curta as seen in cross section (pl. 2, fig. 8). 

Age. -Miocene, Midway. 

Locality. -Midway, reef hole: 754, 762, 768, 778, 789. 

Genus CYPHASTREA Milne Edwards and Haime 1848 

Cyphastrea oeellina (Dana 1846) 

Cyphastrea ocellina Vaughan 1907, p. 103, pl. 25, figs. 4, 5; pl. 26, fig. 1 

(synonymy) 

Worn fragments of this endemic Hawaiian form were 

found in the upper 200 ft of the Sand Island drill hole. 

Age. -Pliocene and Pleistocene, Midway; Holocene, 

Hawaii. 

Locality. -Midway, Sand Island hole: 125-135, 

141-142, 180-185. 

Genus GALAXEA Oken 1815 

Galaxea haligena Felix 1913 

Plate 3, figures 5, 6 

Galaxea haligena Felix 1913, p. 339, pl. 26, figs. 1, 2, 2a-c 

Felix 1923, p. 89 

One specimen, a fragment of a corallum showing 

nothing of the external surface, is referred to this species, which is possibly an early form of the widespread 

Pleistocene and Holocene G. fascicularis (Linnaeus) of 

the Indo-Pacific. The corallites range in diameter from 

4 to 9 mm, mostly 6 to 8 mm, and have externally faint 

costal striations. Septa are in four cycles plus a few very 

short septa of the fifth (48+), those of the first three 

extending to and merging with a well-developed 
FOSSIL CORALS FROM MIDWAY A TOLL G7 

trabecular columella. G. lauensis Hoffmeister 1945, 

from the Miocene of Lau, Fiji, has smaller corallites and 

fewer septa. 

Age. -Miocene, Midway, Borneo; Pliocene, Java. 

Locality. -Midway, reef hole: 494. 

REFERENCES CITED 

Allison, E. C., Durham, J. W., and Mintz, L. W., 1967, New southeast 

Pacific echinoids: California Academy of Sciences Occasional 

Paper 62, 23 p., 32 figs. 

Chevalier, J.-P., 1971, Les scleractiniaires della Melanesie Francaise. 

1 •r partie: Expedition Fran~aise sur les recifs coralliens de la Nouvelle Caledonie, v. 5, 307 p., 38 pls., 182 figs. 

Dana, J. D., 1846-1849, Zoophytes: U.S. Exploring Expedition, v. 7, 

740 p., 45 figs.; atlas, 12 p., 61 pls. (1849). 

Dana, T. F., 1971, On the reef corals of the world's most northern atoll 

(Kure: Hawaiian Archipelago): Pacific Science, v. 25, no.1, p. 80-87, 

6 figs. 

Duncan, P.M., 1880, Sind fossil corals and Alcyonaria: Palaeontologia 

Indica, ser. 14, v. 1., pt. 1, 110 p., 28 pls. 

Ehrenberg, C. G., 1834, Die Corallenthiere des rothen Meeres physiologisch untersucht und systematisch verzeichnet: Akademie der 

Wissenschaften, Berlin, Abhandlungen 1832, p. 225-380, 1 pl. 

Felix, J.P., 1913, Die fossilen Anthozoen aus der Umgegend von Trinil: 

Palaeontographica, v. 60, p. 311-365, pls. 24-27, 3 figs. 

--1921, Fossil Anthozoen von Borneo: Palaeontologie von Timor, 

pt. 9, no. 15, p. 1-64, pls. 1-6, 12 figs. 

Fisher, R. L., ed., 1958, Preliminary report on Expedition Downwind, 

University of California, Scripps Institution of Oceanography, 

IGY cruise to the southeast Pacific: IGY [International Geophysical Year] General Report Series, No. 2, 58 p., 21 figs. 

Gardiner, J. S., ed., 1903-1906, The fauna and geography of the Maldive and Laccadive Archipelagoes: Cambridge, England, Cambridge University Press, 2 v. (See v. 2, suppl. 1, p. 933-957, 

pls. 89-93, Madreporaria: Fungida and Turbinolidae.) 

Gerth, Heinrich, 1921, Anthozoa, in Martin, Karl, Die Fossilen von 

Java***: Geologische Reichsmuseum Leiden Sammlungen, Neue 

Folge, v. 1, Abt. 2, no. 3, p. 387-445, pls. 55-57. 

--1923, Die Anthozoenfauna des Jungtertil:lrs von Borneo: Geologische Reichsmuseum Leiden Sammlungen, Ser. 1, v. 10, p. 37-136, 

9 pls. 

Hoffmeister, J. E., 1945, Corals, in Ladd, H. S., and Hoffmeister, J. E., 

Geology of Lau, Fiji: Bernice P. Bishop Museum Bulletin 181, 

p. 298-311, pls. 31-40. 

Holden, J. C., 1967, Late Cenozoic ostracodes from the drowned terraces in the Hawaiian Islands: Pacific Science, v. 21, no. 1, p. 1-50, 

37 figs. 

Klunzinger, K. B., 1877-1879, Die Korallenthiere des Rothen Meeres: 

Berlin, Gutmann'schen, 3 v. (See pts. 2 and 3, 188 p., 20 pls.) 

Ladd, H. S., Tracey, J. I., Jr., and Gross, M.G., 1970, Deep drilling on 

Midway atoll: U.S. Geological Survey Professional Paper 680-A, 

22 p. 

Maragos, J. E., 1977, Scleractinia, in Section 1 of Devaney, D. M., and 

Eldredge, L. G., eds., Reef and shore fauna of Hawaii: Bernice P. 

Bishop Museum Special Publication 64, p. 158-241, 118 figs. 

Matthai, George, 1948, On the mode of growth of the skeleton in 

fungid corals: Royal Society of London Philosophical Transactions, 

v. 233-B, p. 177-195, pls. 3-14. 

Milne Edwards, Henri, and Haime, Jules, 1857-1860, Histoire naturelle des coralliaires: Paris, Roret, 3 v. and atlas (v. 1, 2 (1857); 

v. 3 (1860); atlas (1857) ). 

Ortmann, A. E., 1889, Beobachtungen an Steinkorallen von der sridknste Ceylons: Zoologische Jahrbncher, Abteilung fnr Systematik***, v .. 4, p. 493-590, pls. 11-18. 

Reuss, A. E., 1867, Ueber fossile Korallen von der Insel Java, in Reise 

der*** "Novara": Geologischer Theil, v. 2, p. 165-185, pls. 1-3. 

Scheer, Georg, 1964, Korallen von Abd-el-Kuri: Zoologische Jahrbncher, Abteilung fnr Systematik***, v. 91, no. 3, p. 451-466, 4 pls., 

3 figs. 

--1967, Korallen von den Sarso-Inseln im Roten Meer: Senckenbergiana Biologica, v. 48, p. 421-436, 14 figs. 

Umbgrove, J. H. F., 1929, Anthozoen van N. 0. Borneo: Dutch East 

Indies, Dienst van den Mijnbouw, Wetenschappelijke Mededeelingen, No.9, p. 47-78, pls. 1-5, 2 figs. 

Vaughan, T. W., 1907, Recent Madreporaria of the Hawaiian Islands 

and Laysan: U.S. National Museum Bulletin 59,427 p., 96 pls., 1 fig. 

Vaughan, T. W., and Hoffmeister, J. E., 1925, New species of fossil 

corals from the Dominican Republic: Harvard College, Museum of 

Comparative Zoology, Bulletin, v. 67, no. 8, p. 315-326, 4 pls. 

Veron, J. E. N., and Pichon, M., 1976, Scleractinia of eastern Australia. 

Part I. Families Thamnasteriidae, Astrocoeniidae, Pocilloporidae: 

Australian Institute of Marine Science Monograph, v. 1, 86 p., 

166 figs. 

--1977, Scleractinia of eastern Australia. Part II. Families Faviidae and Trachyphylliidae: Australian Institute of Marine Science 

Monograph, v. 3, 233 p., 477 figs. 

Wells, J. W., 1954a, Recent corals of the Marshall Islands: U.S. Geological Survey Professional Paper 260-1, p. 385-486, pls. 94-187, 

figs. 119-122. 

--1954b, Fossil corals from Bikini drill holes: U.S. Geological Survey Professional Paper 260-P, p. 609-617, pls. 223-224, 

figs. 167-168. 

--1964, Fossil corals from Eniwetok Atoll: U.S. Geological Survey 

Professional Paper 260-DD, p. 1101-1111, pls. 296-300. 

Yabe, Hisakatsu, Sugiyama, Toshio, and Eguchi, Motoki, 1936, Recent 

reef-building corals from Japan and the South Sea Islands under 

the Japanese Mandate: Tohoku Imperial University Science Reports, 2d ser. (Geology), Special Volume 1, 66 p., 59 pls. 

PLATES 1-3 

Contact photographs of the plates in this report are available at cost from U.S. Geological Survey Library, 

Federal Center, Denver, Colorado 80225 
PLATE 1 

FIGURES 1-6. Stylophora pistillata (Esper) (p. G3). 

1. Latex cast, Xl. Reef hole, 990-993 ft. USNM 62375. 

2, 3. Ecomorph mordax, X10, Xl. Reef hole 638 ft. USNM 62377. 

4,5. Ecomorph mordax, X1, X5. Reef hole, 699 ft. USNM 62378. 

6. Ecomorph mordax, mold, Xl. Reef hole, 701 ft. USNM 62376. 

7-9. Stylophora gem mans Gerth (p. G4). 

7. Mold, Xl. Reef hole, 671-676 ft. USNM 62380. 

8, 9. Latex cast, X1, X5. Reef hole 970-971 ft. USNM 62379. 
GEOLOGICAL SURVEY 

1 

4 

6 

2 

8 

STYLOPHORA 

PROFESSIONAL PAPER 680-G PLATE 1 

3 

7 

5 

9 
PLATE 2 

FIGURES 1, 2. Seriatopora sp. cf. S. hystrix Dana (p. G4). 

1. Latex cast, Xl. Reef hole, 958-959 ft. USNM 62381. 

2. Latex cast, Xl. Reef hole, 963-964 ft. USNM 62390. 

3, 4. Pocillopora sp. cf. P. hemprichi Ehrenberg (p. G5). 

X1, X5. Reef hole, 631-636 ft. USNM 62388. 

5, 6. Acropora sp. (p. G5). 

5. Latex cast, X4. Reef hole, 901-906 ft. USNM 62389. 

6. Mold, X4. Reef hole, 946-951 ft. USNM 62384. 

7. Plesiastrea sp. cf. P. curta (Dana) (p. G6). 

Transverse section, Xl. Reef hole, 754.7 ft. USNM 62374. 

8. Plesiastrea curta (Dana) (p. G6). 

Transverse section, Xl. Holocene, Heron Island, Great Barrier Reefs. USNM 62383. 
GEOLOGICAL SURVEY PROFESSIONAL PP.PER 680-G PLATE 2 

4 

3 

6 

5 

7 8 

SERIATOPORA,POCILLOPORA,ACROPORA, PLESIASTREA 
PLATE 3 

FIGURE 1. Favia sp. A (p. G6). 

Mold, Xl. Reef hole, 1,061-1,066 ft. USNM 62386. 

2. Favia sp. B (p. G6). 

Calices, Xl. Reef hole, 915-916 ft. USNM 62382. 

3. Favites sp. cf. F. chinensis (Verrill) (p. G6). 

Mold, Xl. Reef hole, 915-916 ft. USNM 62387. 

4. Favia sp. C (p. G6). 

Transverse section, Xl. Reef hole, 590-595 ft. USNM 62373. 

5, 6. Galaxea haligena Felix (p. G6). 

5. Transverse section, Xl. Reef hole, 494 ft. USNM 62385. 

6. Vertical section, Xl. Reef hole, 494ft. USNM 62385. 
GEOLOGICAL SURVEY PROFESSIONAL PAPER 680-G PLATE 3 

2 

1 

3 4 

6 

5 

FAVIA, FAVITES, GALAXEA 

-t.- U.S. GOVERNMENT PRINTING OFFICE: 1982 - 361-614/ 326