Ostracoda of 

Late Eocene Age 

From Eua, Tonga

GEOLOGICAL SURVEY PROFESSIONAL PAPER 640-D

Ostracoda of 

Late Eocene Age 

From Eua, Tonga

By JOSEPH E. HAZEL and JOHN C. HOLDEN

LATE EOCENE FOSSILS FROM EUA, TONGA

GEOLOGICAL SURVEY PROFESSIONAL PAPER 640-D

Description and discussion of the 

paleo environment a I significance of 

ostracodes from an upper Eocene 

locality on Eua, Tonga

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1971
UNITED STATES DEPARTMENT OF THE INTERIOR 

ROGERS C. B. MORTON, Secretary

GEOLOGICAL SURVEY 

W. A. Radlinski, Acting Director

Library of Congress catalog-card No. 77-179321

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

Washington, D.C. 20402 - Price 50 cents (paper cover)

Stock Number 2401-1198
LATE EOCENE FOSSILS FROM EUA, TONGA FOREWORD

One of the most widespread units of the Cenozoic 

section in the islands of the open Pacific is a series of 

limestones assigned to the upper Eocene (Tertiary 6). 

Such limestones, containing diagnostic larger Foraminifera, have been reported in many parts of an area 

spreading 4,000 miles across the tropical Pacific (fig. 1), 

from Palau and the Mariana Islands on the northwest 

through the Marshall Islands (Eniwetok) to Fiji and 

Tonga on the southeast (Whipple, in Hoffmeister, 1932, 

p. 79-86 ;Asano, 1939; Cole, 1950, 1957a, 1957b, 1960). 

In almost all the islands the limestones are dense and 

crystalline. Foraminifera and algae are abundant locally, but in most places fossils cannot be extracted and 

must therefore be studied in random thin sections. On 

the little island of Eua, Tonga, a locality was recently 

found where the Eocene limestone is tuffaceous, considerably weathered, and richly fossiliferous. Abundant 

fossils that represent a dozen organic groups were found. 

Such abundance and diversity signaled the find as a 

remarkable one that would add greatly to our knowledge of life in the western Pacific during the Eocene.

The island of Eua measures only 12 by 5 miles but 

it rises 1,000 feet above sea level. It occupies an interesting position tectonically, as its steep eastern side 

faces the Tonga Trench. In addition, Eua is the oldest 

island in the Tonga group that has a plutonic core 

(Guest, 1959) and a series of associated volcanic rocks, 

which are partly blanketed by thick limestones of late 

Eocene age. Younger volcanic rocks and sediments of 

late Tertiary age are also present (Hoffmeister, 1932).

This series of reports is concerned with one facies of 

the upper Eocene limestone. After the limestone series 

was deposited, Eua was uplifted periodically and a 

sequence of six terraces was cut in the limestones on 

the windward (eastern) side. Hoffmeister was the 

first to recognize the Eocene age of the main limestone 

of the terraces, three of which have veneers of Pliocene 

reef corals. He made a planetable map of the terraced 

eastern ridge and recorded the average altitudes of the 

terraces as 100, 200, 340, 400, 550, and 760 feet. The 

east-facing "rocky backbone" of Eua thus looks in 

profile like a giant staircase facing the Tonga Trench. 

The Eocene limestone may once have covered all of Eua

but is now largely limited to the eastern ridge (Hoffmeister, 1932; the Eocene Foraminifera were described by Whipple in this same report, p. 79-86).

The fossils described in this series of reports were 

obtained from an outcrop on the 400-foot terrace 

about a quarter of a mile north of Vaingana (fig. 2). 

At this locality, the limestone lies close to the underlying volcanic rock and is tuffaceous and partly 

weathered; almost everywhere else on Eua the limestone 

is pure, hard, and crystalline.

In 1943, Harold T. Stearns, then of the U.S. Geological Survey, also served as a consultant to the 

Armed Forces at Pacific bases and made a brief 

visit to Eua. He collected a sample that contained 

half a dozen fossil brachiopods from the 400-foot 

terrace on the eastern side of the island. Stearns recorded the locality as: "Tele-a-hiva at elevation 

of 400 feet about }{ mile north of army lookout tower, 

at the second stream north of Vaigana [sic]." The 

brachiopods were examined by G. A. Cooper of the 

U.S. National Museum. Some years later when I 

was studying other island fossils collected by Stearns, 

Cooper showed me the brachiopods and expressed 

a desire for additional specimens so that he could 

continue his study of their internal structures.

In 1966,1 learned that Yoshio Kondo of the Bernice 

P. Bishop Museum in Honolulu intended to visit Eua in 

connection with his studies of living Pacific island land 

snails (under National Science Foundation grant 

GB-3974). I sent Stearns' locality data and marked 

copy of Hoffmeister's Eua map to Kondo, and I informed Stearns of the plan to collect- additional 

material.

Late in August 1967, Kondo reached Eua and, aided 

by a Tongan guide, Tomiki, and an interpreter, Mosese 

Vea, spent 2 days searching for the fossil locality. The 

lookout tower mentioned by Stearns no longer exists 

and Kondo found that Tele-a-hiva translates to "Nine 

Gulches." Traveling northward from "Vaigana" (Otu 

Vaingana) through heavy brush on exceedingly rugged 

karst topography for about 1,000 feet, he reached the 

first of the gulches. There he found a soft fossiliferous 

layer between two harder limestones and collected a
40-pound sample of the material. This gulch locality 

is probably not the exact spot visited by Stearns. The 

two collections have minor differences in nature of 

preservation, but they obviously came from the same 

formation.

In 1969 Wilfred Bryan of the Carnegie Institution 

of Washington collected additional material from the 

locality sampled by Kondo. Bryan's material was 

taken from soft calcareous tuffs 2-3 feet in thickness 

that dipped 30°-40e E. These calcareous tuffs were

FIGURE 1. Location of Tonga and other island groups in the southwest Pacific where upper Eocene limestone has been identified. Dashed line marks structural boundary of the Pacific Basin (andesite line). Islands shown include the surrounding reefs.

IV
directly underlain by several feet of harder fossiliferous material that, in turn, lay above agglomerate 

with truncated dikes. The horizon sampled was at an 

altitude of about 355 feet in a gully notched into the 

400-foot terrace.

The exact extent of the richly fossiliferous bed is 

not known. In 1926, when Hoffmeister made his

FIGURE 2. Map of Eua, Tonga, showing the location of the 

recently discovered fossil outcrop (x) and the main mass 

of Eocene limestone (patterned area) on the east side of 

the island, as mapped by Hoffmeister (1932).

map of the terraces, he did not come upon this fades, 

and in 1928 when I spent 2 weeks on Eua with Hoffmeister, reviewing his mapping, no exposures of this 

zone were seen although we visited Vaingana. Additional fieldwork in the area of the rugged "Nine 

Gulches" would be worthwhile.

William Melson of the Smithsonian Institution 

examined hand specimens and thin sections of the 

tuffaceous limestone and noted that the volcanic constituents are highly altered, making it difficult to 

determine their original nature. The rock is composed of 50 percent or more of volcanoclastic debris, 

much of which has been replaced by calcite. The 

predominant volcanic fragments are of porphyritic 

pumiceous glassy material; most of the phenocrysts 

are plagioclase, now largely replaced by calcite. The 

original groundmass of pumiceous glass is now 

devitrified and dark brown. Fragments of tuff are 

rare. There appears to be a large and varied assemblage of secondary minerals. The volcanic fragments 

are mainly porphyritic andesitic rocks, or possibly 

plagioclase-bearing dacites. The presence of abundant fossils suggests that the volcanic material has 

been reworked.

The soft tuffaceous limestones collected on Eua 

were treated with a wetting agent and penetrant in 

the laboratory. The material broke down easily, revealing a variety of fossil remains: Foraminifera, 

discoasters, corals, hydrozoans, brachiopods, bryozoans, annelids, crinoids, echinoids, ostracodes, 

barnacles, decapod crustaceans, mollusks, shark 

teeth, otoliths, and spores and other plant microfossils.

W. Storrs Cole has described the larger Foraminifera ; these fossils suggest to him a depth of deposition of about 200 feet, but other groups notably the 

smaller Foraminifera, the corals, brachiopods, bryozoans, mollusks, ostracodes, and barnacles point to 

a considerably greater depth of deposition.

Material representing a total of 17 organic groups 

was distributed to paleontologists for study and report. Seven of these collections were small or were 

made up of incomplete specimens leading only to 

summary reports, but the others, except for the 

larger Foraminifera, contained much new material. 

The brachiopod, bryozoan, ostracode, barnacle, and 

mollusk collections contained the first identifiable 

Eocene species from the islands of the open Pacific, 

an area extending 4,000 miles from Palau to Tonga.

HARRY S. LADD

CONTENTS

Page

Foreword . . ......... ............ .............................. Ill

Abstract .... ......... ........ ....................................... Dl

Introduction ... ..... ............... ........................................... 1

Paleoenvironment ... ................. ............ ............. 1

Pave

Systematic paleontology D2

References cited ._.... ...... - - - .. . 9

Index . _ .. . 11

ILLUSTRATIONS

[Plates follow index]

PLATE 1. Jugosocythereis, Pokornyella, Nephokirkost, Tongacythere, Bradleya, and Polycope.

2. Cytheropteron, Paracytheridea, Bythocytheremorpha, Bythocypris, Paradoxostoma, Neonesidea, Paranesidea, 

Macrocypris, Bythocythere, Cytherella, and "Neonesidea," Paranesideat

3. Cytheropteron, Nephokirkosl, Paracytheridea, Bythocytheremorpha, Tongacythere, Jugosocythereis, Pokornyella, Krithe, and Bradleya.

4. Bythocythere, Paranesidea, "Neonesidea," Neonesidea, Macrocypris, Paranesideal, and Havanardia.

5. Cytherella, Bythocypris, Argilloecia, Macrocyprisl, Paradoxostoma, and Sclerochilus. PaTe

FIGURE 1. Map showing the location of Tonga and other island groups in the southwest Pacific where upper Eocene limestone has been identified . ....................... ..........__.. .. .._. ............. .._...... .._... . . . IV

2. Map of Eua, Tonga, showing the location of the recently discovered fossil outcrop and the main mass of

Eocene limestone ............... ............................................................................................ ..... ......................... ... V

3. Scattergram of length versus height for Bradleya tongaensis n. sp. . ....... ..._.....- ... .................... Ti

4. Scattergram of length versus height for Bythocypris vainganaensis n. sp. and B, proreniformis n. sp................ 7

TABLE

TABLE 1. Ostracode species in the sample from Eua, Tonga

PaTe 

12

VII

LATE EOCENE FOSSILS FROM EUA, TONGA

OSTRAGODA OF LATE EOCENE AGE FROM EUA, TONGA

By JOSEPH E. HAZEL and JOHN C. HOLDEN l

ABSTRACT

Thirty-one species of late Eocene ostracodes were found in 

a tuffaceous limestone on the island of Eua, Tonga. Of these, 

10 species account for 80 percent of the 288 specimens found. 

The assemblage is dominated by Bythocypris, Bradley a, Macrocypris, Bythocytheremorpha, Bythocythere, and a new 

thaerocytherine genus, Tongacythere. These abundant forms 

at least are considered to represent the autochthonous part of 

the assemblage; their presence indicates deposition in the 

bathyal zone.

Many of the rare species in the collection belong to genera 

whose living species are adapted to life in sublittoral habitats. 

Among the rare genera are Paradoxostoma and Sclerochilus, 

which are eurythermal shallow-water forms, and Pokornyella, 

Paracytheridea, Jugosocythereis, Neonesidea, and Paransidea, 

which are thermophilic shallow-water forms. These taxa are 

considered to represent an allocthonous assemblage. It is suggested that the bathyal site of deposition was very near a 

tropical sublittoral environment.

Six of the more abundant species are described and named 

in this report; the remainder are left in open nomenclature. 

The new taxa are Tongacy there kondoi, Bradleya tongaensis, 

Bythocytheremorpha pacifica, Bythocypris vainganaensis, B. 

proreniformis, and Macrocyprisl dimorpha.

INTRODUCTION

Early Tertiary marine Ostracoda are virtually 

unknown from the islands of the open Pacific, the 

Indonesian area, Australia, and the margins of the 

continents that surround the Pacific Ocean. Only for 

New Zealand, as a result of the work by Hornibrook 

(1952, 1953), is there a usable literature. The ostracodes recovered from the upper Eocene (Globigerina 

gortanii zone) limestone one-fourth mile north of 

Vaingana, Eua, Tonga, at an altitude of 400 feet 

(USGS Cenozoic loc. 24686), are therefore of more 

than ordinary interest (see foreword, p. III-V; Todd, 

1970).

A total of 288 specimens of ostracodes was extracted from the washed residue of about a kilogram

1 National Oceanic and Atmospheric Administration, Miami, Fla. 33130.

of raw sample. More than 80 percent of the specimers 

belongs to only 10 of the species recovered. Because 

adult well-preserved specimens of the 21 remaining 

species are very rare, these forms are poorly understood. Specimens of all the species are illustrated, but 

the 21 rare species and four of the 10 commonly 

occurring forms are left in open nomenclature; most 

of these rare forms appear to have been transported 

to the site of deposition. Six species and one genus 

are proposed as new.

PALEOENVIRONMENT

The assemblage is dominated by Bythocypris vainganaensis and B. proreniformis, which together 

account for 44 percent of the individual specimen^, 

Bradleya tongaensis (15 percent), Macrocyprisl dimorpha and M. sp. (8 percent), Bythocytheremorpha pacifica (5 percent), Tongacy there kondoi (4 

percent), and Bythocythere sp. (3 percent). Living 

Bythocypris are typical inhabitants of deep, mainly 

bathyal, waters (Morkhoven, 1963; Haddocks, 1969). 

Bradleya tongaensis is a species of the B. dictyon 

(Brady, 1880) complex, which is a deep-sea group in 

modern seas (Brady, 1880; Benson, 1969). Macrocypris is also more commonly found in deep water than in 

sublittoral habitats (Morkhoven, 1963). Bythocytheremorpha pacifica is most similar to the living B. 

tuberctilata, described by Chapman (1910) from just 

north of Fiji in 2,200 meters of water. Tongacythere 

is a thaerocytherine, and members of this subfamily 

are not uncommon in deep water (for example, Bradleya and Thaerocythere). Bythocythere occurs commonly in both sublittoral and bathyal habitats. The 

abundant species of these dominant genera in the 

collection are considered to represent the authochthonous part of the assemblage. Their presence incMcates deposition of the enclosing sediment in the 

upper bathyal zone.

Di
D2 LATE EOCENE FOSSILS FROM EUA, TONGA

In contrast, many of the rare species belong to 

genera whose living species are adapted to life in sublittoral habitats. Present are such taxa as Paradoxostoma and Sclerochilus, which are eurythermal 

shallow-water forms, and Jugosocythereis, Pokornyella, Paracytheridea, Paranesidea, and Neonesidea, 

which are thermophilic shallow-water forms. Specimens of these genera were probably transported to 

the site of deposition from a very nearby shallowwater habitat.

Table 1 lists all the species found in the Eua collection and gives the number of specimens found of each 

species. The temperature tolerance and general depth 

range of the genera based on the known distribution 

of living species are also given. In the last column, 

we have listed our conclusions as to whether the 

species was a member of the autochtonous or allocthonous part of the assemblage.

SYSTEMATIC PALEONTOLOGY

All measurements of the specimens are in microns. 

Abbreviations used for dimensions are as follows: L, 

H, and W for length, height, and width, respectively. 

The number of specimens measured (N) is followed 

by the mean value of the dimension (M), its standard

deviation (Sd), its observed range (OR), and its coefficient of variation (V). The statistics are based on 

adult specimens. All type specimens have been deposited in the collections of the U.S. National Museum, 

Washington, D.C.

Order PODOCOPIDA Sars, 1865

Suborder CYTHEROCOPINA Griindel, 1969

Superfamily CYTHERACEA Baird, 1850

Family HEMICYTHERIDAE Puri, 1953

Subfamily THAEROC YTHERINAE Hazel, 1967

Genus TONGACYTHERE Hazel and Holden, n. gen.

Type species, Tongacythere kondoi n. sp.

Diagnosis. Rectangular in lateral view; surface 

coarsely pitted; well-developed caudal process at midheight; alate; spines developed at posteroventral angles of both valves and posterodorsal angle of right 

valve; hinge strong amphidont, posterior tooth of 

right valve faintly lobed; four elongated adductormuscle scars on back edge of muscle pit,, two frontal 

scars anterior to these, lower frontal scar larger.

Discussion. Tongacythere differs from Hermanites Puri and Cletocythereis Swain, which may be 

congeneric, in the development of the prominent caudal process and in being more alate. The posterodorsal and posteroventral spines also distinguish Tongacythere from these two related genera.

TABLE 1. Ostracode species in the sample from Eua, Tonga

Species

Subfamily Thaerocytherinae :

Subfamily Hemicytherinae: 

Pokornyella sp ....... _..._ ...._ ._. _ . ......

Subfamily Bythocytherinae:

Subfamily Cytheropterinae:

sp. 2 .............. _... ._. _ .....

sp. 3- ... . -

Subfamily Krithinae:

Subfamily Paradoxostomatinae:

Subfamily Macrocypridinae:

Subfamily Bythocypridinae:

Subfamily Bairdiinae:

sp. 2

sp. 2 .... ..__ ..__ .

sp. 3

Subfamily Pontocypridinae:

Subfamily Cytherellinae:

Subfamily Polycopinae: 

Polycope sp .. ._._.. .. .......

Number of 

specimens

11

42

.. _ _ . 4

1

1

10

13

1

3

1

1

1

8

2

1

7

........ .......-- ... 15

52

74

3

1

5

3

2

5

7

2

2

5

1

Temperature 

tolerance 

of genus

t 1 )

do

Warm temperate-tropi(

do

. ._.. _.___dO 

do

Tropical (?) .... ..... _ ..

do

do

do

Depth range 

of genus

O)

do

t 1 )

:al ...Sublittoral ..._........ _ ... ..

do

do

_.... .do... ..

. .. . do... 

-Sublittoral (?) . 

.. _ . Sublittoral............. ........

do

.. Eurybathic ._... .. _ ._. .

.. __ ......do __

do

Autochthonous 

or allocthonous

Autochthonous . 

......... Do.

........ Do.

Do.

Do.

Do. 

Do.

_ Allocthonous.

Autochthonous.

.. ... Allocthonous.

Do.

Autochthonous.

Do. 

Do.

Do. 

Allocthonous.

Do.

Do. 

Uncertain. 

 .... Allocthonous.

Do. 

Do.

Do. 

Uncertain.

. _ _____ Autochthonous.

Do.

Uncertain.

1 Genus extinct.
OSTRACODA D3

Tongacythere kondoi n. sp.

Plate 1, figures 6-9, 18, 19; plate 3, figures 12,13, 20

Description. Shell thick; subrectangular in lateral 

view, valves unequal, left valve having large bullar 

process above posterior hinge socket and massive 

anterodorsal flangelike process in front of anterior 

hinge elements, right valve not having these structures; left valve overlapping right valve slightly at 

anterocardinal and posterocardinal angles and along 

top of well-developed caudal process; left valve overreaching right valve strongly at anterodorsal and 

posterodorsal areas; surface coarsely reticulate, five 

or six large fossae above strong ala; poorly developed 

vertical ridge from ala posterior to short horizontal 

dorsolateral ridge; subcentral tubercle small, circular, prominent; marginal rims well developed, especially anteriorly, and smooth; anterior margin having 

about 12 denticles; posteroventral margin spinose 

having one conspicuously large spine; caudal process 

large, elongate, upturned, at midheight. In dorsal 

view, carapace arrowhead shaped; length 1^ times 

width; compressed in posterior quarter; compressed 

anterolaterally; alae terminating in outward pointing 

spine. Duplicature moderately wide, nonvestibulate, 

transversed by several straight simple radial pore 

canals, numbering some 25 anteriorly, about six clustered in caudal process; normal pores small. Strongly 

developed amphidont hinge, median bar crenulate; 

posterior tooth of right valve faintly lobed. Four adductor scars on back edge of deep subcentral depression; two frontal scars in front of adductor group, 

lower frontal scar larger; small knob above subcentral depression. Sexual dimorphism not apparent.

Material. One adult carapace, eight adult single 

valves; one penultimate left valve, one other juvenile.

Holotype. Left valve, USNM 651466, 874 /z (microns) long and 438 //, high.

Measurements, in microns. 

M Sd OR

L 

H

W

442

17

21

825-875

415-475

575

1.9

4.8

Discussion. A juvenile representative of this or 

at least a closely related species is in a small collection 

of specimens taken from rock samples dredged from 

a depth of 1,116 meters six miles west of Palau, Caroline Islands (RV Pioneer, dredge sample 22,1964).

Genus BRADLEYA Hornibrook, 1953

Bradleya tongaensis n. sp. 

Plate 1, figures 10-12,14-17, 20, 21; plate 3, figure 21

Type species, Cythere arata Brady, 1880. 

Diagnosis. Distinguished by a straight alar ridge

positioned low on the valve and resulting flat venter; 

reticulate subcentral tubercle well developed, grading 

posterodorsally with reticulate surface of valve.

Description. In lateral view, carapace subquadrate, males more elongate, straight dorsal margin 

subparallel having slightly concave ventral margin, 

converging slightly toward posterior; anterior margin denticulate, obliquely rounded, somewhat flattened in dorsal half; posterior margin bluntly roun ded, denticulate, having some larger denticles in 

ventral part; valves having two well-developed ridges, 

one extending from top of subcentral tubercle to posterodorsal angle along dorsum, the other from e:re 

tubercle at anterodorsal angle, paralleling anterior 

margin, running along outer edge of large alalike 

swelling, terminating in prominent, outward pointing 

spine. Surface of valves covered by large fossae; fix 

fossae bordering anterior margin, small ridges separating fossae with small elongated pits on upper surface. In dorsal view, carapace arrowhead shaped, 

greatest width in posterior quarter at alar spines; 

posterolateral surfaces compressed.

Hinge amphidont; in right valve, anterior tooth 

smooth except in front where steplike; median elements consisting of postjacent socket and smooth 

groove; posterior tooth reniform, large, bilobate; 

lobation showing only on underside. Duplicature relatively narrow, no vestibules; well-developed selvage 

groove of right valve continuous, inner list well developed. Radial pore canals apparently simple, straight, 

abundant; many false canals extending through marginal denticles. Normal pores large, forming larnre 

pits on inner valve surface; pores tend to correspond 

with fossae of outer surface, but some extend through 

ridges between fossae. Muscle pit large, deep; fc*ir 

adductor-muscle scars positioned on posterior e<?ge 

of pit, second scar from top largest and most elongated.

Material. 14 adults, 21 penultimate instars, and 

seven younger instars.

Holotype. Female left valve, USNM 651472,1,C20 

fji long and 581 /u, high.

Measurements, in microns (see fig. 3). 

M Sd OR

Female: 

L 

H

Male: 

L 

H 

W

1,004

548

554

21

26

964-1,030 

506-581

1,052-1,090

531-575

392

2.1 

4.7

1.4 

3.4

Discussion. This species is morphologically similar to Bradleya dictyon (Brady, 1880) and belongs to 

that Cenozoic species complex. It differs from B. dictyon (as illustrated by Hornibrook, 1952) in having
D4 LATE EOCENE FOSSILS FROM EUA, TONGA

500

400

300

200

5

II 1 1 1 1 II 1

 Bradleya tot

-

-

:

-

-

~i i i

II 1 1 1 1 II 1

gaensis n. sp.

O

*

ii i i i i i

1 1 1 1 III

0 0

»

i i i

1 1 1 I II

O °* v°

1 1 1

1 1 1

<

III i

1 1 1 1 1 O 

0 0 0

 °

1 

:

-

-

-

ii i

DO 600 700 800 900 1000 11C

LENGTH, IN MICRONS

FIGURE 3. Scattergram of length versus height for Bradleya tongaensis n. sp. O, carapaces and left valves; , right valves.

a lower and straighter alar ridge, which results in a 

flat venter. In addition, there is no well-developed 

median ridge in B. tongaensis.

Genus JUGOSOCYTHEREIS Puri, 1957

Jugosocythereis sp. 

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

Type species, Cythereis bicarinata Swain, 1956.

Discussion. Four somewhat poorly preserved 

specimens of a species of this Indopacific-Caribbean 

shallow-water genus are in the collection. The specimens are considered allocthonous. The single male 

specimen is 875 ^ in length and 475 p in height; 

females varied from 787 to 838 fj. in length and from 

450 to 488 (JL in height; one female carapace was 475 p 

wide.

Subfamily HEMICYTHERINAE Puri, 1953 

Genus POKORNYELLA Oertli, 1956

Pokornyella sp. 

Plate 1, figure 3; plate 3, figure 16

Type species, Cythere limbata Bosquet, 1852.

Discussion. One apparently adult carapace of this 

primarily Tethyan genus is in the material. It is similar to specimens of Pokornyella limbata (Bosquet, 

1852) but possesses a more sinuous ventral outline 

and coarser pitting. The specimen is 626 ^ long, 411 JJL 

high, and 302 (JL wide. It is considered to have been 

transported to the site of deposition.

Genus NEPHOKIRKOS Howe, 1951

Nephokirkos? sp. 

Plate 1, figures 4, 5; plate 3, figure Z

Type species, Nephokirkos aquaplanus Howe, 1951.

Discussion. One carapace of a winged pokornyellid is in the collection. It is somewhat similar to 

Nephokirkos aquaplanus Howe, 1951, but is larger 

and relatively shorter than that species. It is tentatively assigned to Nephokirkos. The specimen is 725 

fjL long, 450 fJL high, and 525 p wide.

Family BYTHOCYTHERIDAE Sars, 1926

Subfamily BYTHOCYTHERINAE Sars, 1926

Genus BYTHOCYTHERE Sars, 18f5

Bythocythere sp. 

Plate 2, figure 18; plate 4, figures 1, 3

Type species, Bythocythere turgida Sars, 1865.

Discussion. Four adult and six juvenile valves of 

a typical representative of this genus ar? in the collection. None are particularly well preserved. The 

adults vary in length from 779 to 851 p and in height 

from 264 to 275 (JL. The species was probably 

autochthonous.

Genus BYTHOCYTHEREMORPHA Mandelstam, 1958

Bythocytheremorpha pacifica n. sp.

Plate 2, figures 3, 6, 12-14,16;

plate 3, figures 6, 7,17,18

Type species, Cytherina umbonata Williamson, 

1847.
OSTRACODA D5

Diagnosis. Large bulbous swelling on anterodorsolateral surface; prominent anterodorsal tubercle.

Description. Strongly alate; each valve having 

four prominent processes: (1) eye tubercle at anterodorsal angle, (2) large hemispherical swelling, 200 p 

wide, near dorsum just anterior to midlength, (3) 

posteroventral ala terminating in spine, (4) anterior 

swelling of alar ridge. All surfaces reticulate; left 

valve overlapping right valve above caudal process, 

anterodorsal angle, and ventral inturned area. Dimorphism not apparent. In lateral view, carapace 

wedge shaped; dorsal margin straight to posterodorsal area, profile broken by two dorsal swellings in 

anterior half; dorsal margin above caudal process 

slightly concave, ventrally inclined from horizontal 

dorsum; ventral margin broadly and evenly rounded 

to caudal process; anterior margin subtruncate, posterodorsal angle roughly 90°. In dorsal view, widest 

in posterior third at alae which project at almost 

right angles to valves, width equal to length; dorsolateral areas highly compressed, widening ventrally 

to greatest width at horizontal alar ridge running 

anterior to ala in ventral quarter.

Internally, large dorsolateral exterior tubercle and 

eye tubercle represented by deep sinuses; hinge of 

left valve having terminal sockets separated by long 

straight slightly crenulate bar that is thickened at 

ends; right valve complimentary.

Material. Eight adult valves; five juveniles.

Holotype. Left valve, USNM 651490, 950 ^ long 

and 438 p wide.

Measurements, in microns. 

N M Sd OR

947

431

10

24

938-950 

400-438

0.6 

5.5

Discussion. Bythocytheremorpha pacifica is somewhat similar to such Cretaceous species as B. bispinata (Weber, 1934), B. trituberculata (Herrig, 1963), 

and B. montuosa (Jones and Hinde, 1890), from 

which it is easily distinguished by the large dorsolateral swelling. More similar is the living Pacific 

species B. tuberculata (Chapman, 1910) which possesses the dorsolateral swelling but which does not 

have the well-developed eye tubercle and is less 

acuminate at the posterior.

Family CYTHERURIDAE Reyment, 1961 

Subfamily CYTHEROPTERINAE Hanai, 1957

Genus CYTHEROPTERON Sars, 1865

Type species, Cythere latissima Norman, 1865.

Discussion. Four species in the Eua collection are 

referable to the genus Cytheropteron. Because the 

genus is a euryvalent taxon, it is unclear whether 

these species were autochthonous or allocthonous.

Cytheropteron sp. 1 

Plate 2, figure 1; plate 3, figures 8, 10

Discussion. This species is represented by a single 

left valve measuring 600 ft in length and 312 fi in 

height.

Cytheropteron sp. 2 

Plate 2, figure 7; plate 3, figures 1, 5

Discussion. This species is represented by two 

adult left valves and one adult right valve. The illustrated specimen is 312 ft long and 250 JJL high.

Cytheropteron sp. 3 

Plate 2, figure 11; plate 3, figure 3

Discussion. This species is represented by a single 

carapace, 403 p long, 279 ft high, and 256 ft wide.

Cytheropteron sp. 4 

Plate 3, figures 9, 11

Discussion. The single left valve is 475 JJL long and 

312 fji high.

Family PARACYTHERIDEIDIDAE Puri, 1957

Subfamily PARACYTHERIDEIDINAE Puri, 1957

Genus PARACYTHERIDEA Miiller, 1894

Paracytheridea sp. 

Plate 2, figure 2; plate 3, figure 4

Type species, Paracytheridea depressa Miiller, 

1894.

Discussion. A single specimen of a Paracytheridea, somewhat similar to P. hispida Bold, 1946, from 

the Eocene of Bonair, is in the collection. The adult 

right valve measures 620 ft in length and 267 ft in 

height. The specimen was probably transported to the 

bathyal site of deposition from a sublittoral habitat.

Family KRITHIDAE Mandelstram, 1958

Subfamily KRITHINAE Mandelstram, 1958

Genus KRITHE Brady, Crosskey, and Robertson, <1874

Krithe sp. 

Plate 3, figure 19

Discussion. Several specimens of a fairly typical 

Krithe of the K. elongata Bold, 1960, type were found 

in the Eua material. Not enough comparative material is available for us to make a decision as to 

whether our specimens represent a new species. The 

species was probably autochthonous.

Measurements, in microns. 

N OR

Female: 

Z, 

H

Male: 

Z, 

H

608-630 

316-335

700-742 

290-325
D6 LATE EOCENE FOSSILS FROM EUA, TONGA

Family PARADOXOSTOMATIDAE Brady and Norman,

1889 

Subfamily PARADOXOSTOMATINAE Brady and Norman,

1889 

Genus PARADOXOSTOMA Fischer, 1855

Paradoxostoma sp. 

Plate 2, figure 5; plate 5, figure 14

Type species, Paradoxostoma dispar Fischer, 1855.

Discussion. One male and one female carapace 

are in the collection; the male is 730 ft long, 320 ft 

high, and 216 ft wide; the female is 657 ft long, 299 ft 

high, and 218 ft wide. The species almost certainly 

was transported to the bathal site of deposition from 

a shallow-water habitat.

Genus SCLEROCHILUS Sars, 1868

Sclerochilus sp.

Plate 5, figure 16

Type species, Cythere contorta Norman, 1862.

Discussion. One specimen of this predominantly 

shallow-water genus is in the collection. The adult 

left valve measures 664 ft microns in length and 333 ft 

in height.

Suborder BAIRDIOCOPINA Grundel, 1967

Superfamily BAIRDIACEA Sars, 1888

Family MACROCYPRIDIDAE Muller, 1912

Subfamily MACROCYPRIDINAE Muller, 1912

Genus MACROCYPRIS Brady, 1868

Type species, Cythere minna Baird, 1850.

Macrocypris sp.

Plate 2, figure 15, 19; plate 4, figure 10

Discussion. A typical species of Macrocypris is 

represented by four adult and three juvenile specimens, all carapaces, in the collection. Without knowledge of the internal features, this species is very 

difficult to distinguish from many species of the 

genus. Three adult females range in length from 

1,240 to 1,266 ft in height from 510 to 512 ft, and in 

width from 410 to 456 ft. The single male is 1,386 ft 

long, 488 ft high, and 386 ft wide.

Macrocypris? dimorpha n. sp. 

Plate 5, figures 8,11,13,17,19

Diagnosis. Carapace robust, length about 600- 

680 ft; strong sexual dimorphism, supposed males being posteriorly sharply pointed; shell thick; valve 

overlap prominent.

Description. Carapace robust, of moderate size; 

strong sexual dimorphism, males sharply pointed 

posteriorly, females bluntly pointed, shorter; wellpreserved specimens very finely pitted; right valve 

larger, overlapping left valve along all margins except middorsum where left valve overlaps right valve.

In lateral view, carapace subtriangular, greatest 

height at angulation just anterior to midlength in 

females or in the anterior third in male?; middorsal 

margin straight to slightly rounded; anterior margin 

broad, obliquely rounded, flattened in the dorsal half; 

posterior margin bluntly pointed in femr.les, sharply 

pointed in males, slightly upturned in bcth sexes. In 

dorsal view, carapace asymmetrically lenticular, anterior and posterior extremities sharply pointed, posterior more acuminate in males; greatest width just 

anterior to midlength in females or in anterior third 

in males; trace of valve junctures irregular.

Material. 14 adults, most entire; one penultimate 

juvenile.

Holotype. Female carapace, USNM 651442, 575 ft 

long, 300 ft high, and 262 ft wide.

Measurements, in microns. 

N M Sd OR

Female:

L

H

W

10

10

8

587

299

249

19

8

5

562-616

288-316

243-2»2

3.2

2.5

2.0

Male: 

L 

H 

W

266

215

50

18

16

562-6 ") 

250-234 

204-239

8.2 

6.8 

7.7

Discussion. This species is questionably placed in 

Macrocypris. It is smaller than most species that have 

been referred to Macrocypris, and none of the specimens of M. ? dimorpha possessed well-preserved 

muscle scars. The species is morphologically similar 

to Macrocypris parva Kaye, 1965, from the middle 

Barremian of the British Isles, but it is larger than 

that species and has a more evenly rounded anterior 

and an upturned posterior.

Family BAIRDIIDAE Sars, 1888 

Subfamily BYTHOCYPRIDINAE Maddocks, 1969

Genus BYTHOCYPRIS Brady, 1881

Type species, Bythocypris reniformis Brady, 1880.

Bythocypris vainganaensis n. sp. 

Plate 2, figure 4; plate 5, figures 3, 4, 9,10

Description. Carapace stout; dimorphism not apparent; adults varying in length from 900 to 975 ft; 

surface of valves smooth; left valve larger, strongly 

extended over right-valve side along entire dorsal 

margin; left valve overlapping right valve at anterodorsal and posterodorsal regions, around posterior, 

ventral inturned area. In lateral view, carapace elongate subovate, dorsal margin broadly rounded in posterior two-thirds, flattened in anterior third; posterior 

margin bluntly rounded; ventral margin straight, 

sometimes very gently convex or concave; anterior 

margin sloping backward, somewhat flattened in ventral half. In dorsal view, carapace anteriorly and pos-
OSTRACODA E7

teriorly bluntly pointed; width equal to one-third 

length; greatest width in posterior third; centrolateral area flattened, converging somewhat anteriorly.

Hinge adont, middorsum of right valve fitting into 

shallow groove of left valve; duplicature well developed, especially large anteriorly, present in adult 

valves only; anterior vestibule deep; posterior vestibule shallow. Radial pore canals straight, apparently 

bifurcating near anteroventral margin; normal pores 

abundant, very small, simple type. Adductor-muscle 

scar pattern circular cluster of four oblong scars 

(bythocyprid pattern).

Material 17 adults; 14 penultimate instars; 14 

sixth-stage instars; seven fifth-stage instars.

Holotype. Carapace, USNM 651446, 925 //, long, 

463 fji high, and 362 ^ wide.

Measurements, in microns (see fig. 4). 

N M Sd OR

17

14

936

465

25

27

900-975 

391-520

2.6 

5.8

Discussion. This species is smaller than Bythocypris proreniformis and relatively more elongate 

and more bluntly rounded at the posterior than that 

species.

Bythocypris proreniformis n. sp. 

Plate 2, figure 22; plate 5, figures 12,15, 18

Diagnosis. Large, up to 1,330 ju in length; dorsum 

evenly arched; posterior bluntly pointed, near venter

as seen from the side; as seen from above carapace 

lenticular, extremities sharply pointed.

Description. Carapace large, adults variable in 

size from about 1,130 to 1,330 ju; sexual dimorphism 

not apparent; surface of valves smooth; left valve 

larger, overlapping right valve along all margins, 

more so along middorsum and ventral inturned area. 

In lateral view, carapace greatest height just anterior 

midlength; dorsum greatly and evenly arched; ventral margin slightly concave downward. In dorsal 

view, carapace lenticular, evenly rounded along entire 

length; greatest width at midlength; extremities 

sharply pointed.

Material. 17 adults; 23 penultimate instars and 

34 other juvenile specimens.

Holotype. Female carapace, USNM 651449,1,213 

ft long, 650 ft high, and 450 ft wide.

measurements, in microns ^see aiso iig. it). 

Female:

Z,

H

W

Male:

L

H

W

N

14

14

15

2

2

2

M

1,189

610

445

Sd

41

27

31

OB

1,130-1,274

578-658

412-512

1,300-1,335

651-696

480-502

V

3.4

4.4

7.0

__._

Discussion. Bythocypris proreniformis is very 

similar to B. reniformis Brady, 1880. It is slightly 

more acuminate at the posterior than B. reniformis 

(see the illustrations in Haddocks, 1969, p. 89).

/uu

600

C/3 

Z

§ 500 

O

z

X 

O 

uj 400

X

300 

?nn

I

Bythocypr

-

-

 A 

1

EXPLANATION 

is vainganae 

is prorenifor

 i

± A

1

1 

w* 09 O Tl QTI ___

vn is n. sp.

A 

A A

1

1

 1

* <

V

1

A

A 

A

A 

A

* I A

1

* it*

»

A

1

1

A 

A

A 

A

1

1

1

1

AA

A

1

-

-

-

1

400 500 600 700 800 900 1000 

LENGTH, IN MICRONS

1100 1200 1300 1400

FIGURE 4. Scattergram of length versus height for Bythocypris vainganaensis n. sp. and B. proreniformis n. sp.
D8 LATE EOCENE FOSSILS FROM EUA, TONGA

Subfamily BAIRDIINAE Sars, 1888 

Genus HAVANARDIA Pokorny, 1968

Havanardia sp. 

Plate 4, figures 15, 22, 23

Type species, Havanardia havanensis Pokorny, 

1968.

Discussion. One adult specimen and two juveniles 

of this winged bairdiid were found. The only known 

living species of the genus, H. havanensis, was found 

in shallow water off Cuba (Pokorny", 1968). Havanardia sp. was possibly transported to the site of deposition from an adjacent sublittoral habitat. The adult 

left valve is 712 p long and 440 /-t high.

Genus PARANESIDEA Maddocks, 1969

Type species, Paranesidea fracticorallicola Maddocks, 1967.

Discussion. Three species in the collection are assigned, one provisionally, to this genus. All are rare, 

and at least the two species assigned with some confidence to the genus probably were transported from 

shallow water (See Maddocks, 1969, for a discussion 

of the ecology of Paranesidea.)

Paranesidea sp. 1 

Plate 4, figures 19-21

Discussion. The single specimen, a carapace, 

measures 742 p in length, 460 ^ in height, and 442 ^ 

in width.

Paranesidea sp. 2 

Plate 2, figures 9,10; plate 4, figures 2, 9

Discussion. Five specimens, three carapaces and 

two left valves, of this pitted form are in the collection. The specimens range from 738 to 800 ^ in 

length, 431 to 470 p in height, and 295 to 321 p in 

width. This species and the preceding one are very 

similar morphologically to such species as the type 

species of the genus, P. fracticorallicola, and P. spongicola and P. algicola, all described from very shallow 

water reef or reef associated habitats at Nosy Be, 

Madagascar, by Maddocks (1969).

Paranesidea? sp. 3 

Plate 2, figure 25; plate 4, figure 13,16

Discussion. This form is represented by three 

carapaces in the collection. There are many bairdiids 

of this general shape; without data on internal features, a confident generic assignment is not possible. 

The three specimens range from 1,240 to 1,370 JJL in 

length, 612 to 773 ^ in height, and 623 to 650 ^ in 

width.

Genus NEONESIDEA Maddocks, 1969

Type species, Triebelina schultzi Hartmann, 1962.

Discussion. Four bairdiid species in the Eua material appear referable to Neonesidea on the basis of 

shape and ornamentation. However, corfirmation of 

this from muscle-scar data is lacking because of the 

type of preservation. All four species are rare and, 

if the generic assignment is correct, ar^ very probably allochthonous. A fifth species, "Neonesidea" sp. 

5, is provisionally placed under Neonesidea, although 

it almost surely doesn't belong here.

Neonesidea sp. 1 

Plate 2, figure 8; plate 4, figures 6,14

Discussion. This form is morphologically similar 

to Neonesidea hanuamaensis (Holden, 1967) but is 

much more compressed. Two carapaces were found. 

The illustrated specimen is 697 p long, 319 ^ high, 

and 239 /-t wide.

Neonesidea sp. 2 

Plate 2, figure 23; plate 4, figures 7, 8

Discussion. Two adult carapaces, one right valve, 

and two instars are assigned to this large species. The 

adults range in length from 1,520 to 1,545 p, in height 

from 926 to 928/*, and in width from 63? to 645 p.

Neonesidea sp. 3 

Plate 2, figure 24; plate 4, figures 17,18

Discussion. One adult carapace, one adult right 

valve, and five instars are assigned to this species. 

The two adults measure 985 and 1,060 /-t in length. 

The carapace is 594 JJL high and 532 ^ wide.

Neonesidea sp. 4 

Plate 2, figure 17; plate 4, figures 11,12

Discussion. Two carapaces, ranging from 1,124 

to 1,165 fji in length, from 585 to 612 p in height, and 

from 424 to 432 JJL in width, are assigned to this 

species.

"Neonesidea" sp. 5 

Plate 2, figure 21; plate 4, figures 4, 5

Discussion. Two apparently adult carapaces of 

this bairdiid were found. The generic assignment is 

in doubt. The species is somewhat similar to the Holocene "Bairdia" fortificata (Brady, 1880) dredged 

from near Booby Island. The two specimens measure 

1,150 and 1,160 ^ in length, 720 and 725 ^ in height, 

and 450 and 456 /-t in width.
OSTRACODA D9

Superfamily CYPRIDACEA Baird, 1845

Family CYPRIDIDAE Baird, 1845 

Subfamily PONTOCYPRIDINAE Miiller, 1894

Genus ARGILLOECIA Sars, 1865

Type species, Argilloecia cylindrica Sars, 1865.

Argilloecia sp. 

Plate 5, figure 5, 6

Discussion, Three adult and two juvenile specimens of an Argilloecia that was probably from the 

autochthonous part of the assemblage are in the collection. The adults are all right valves ranging in 

length from 603 to 606 /* and in height from 280 to 

291 ^.

Order PLATYCOPIDA Sars, 1865

Family CYTHERELLIDAE Sars, 1865

Subfamily CYTHERELLINAE Sars, 1865

Genus CYTHERELLA Jones, 1849

Type species, Cytherina ovata Roemer, 1840.

Cytherella sp. 

Plate 2, figure 20; plate 5, figures 1, 2, 7

Discussion. Four valves of a large species of this 

genus are in the collection, two apparently adult right 

valves, a male and a female, and two juveniles. The 

male is 1,075 p long and 613 p high, and the female 

is 1,100 fj, long and 650 p high.

Order MYODOCOPIDA Sars, 1865 

Suborder CLADOCOPINA Sars, 1865

Family POLYCOPIDAE Sars, 1865 

Subfamily POLYCOPINAE Sars, 1865

Genus POLYCOPE Sars, 1865 

Type species, Polycope orbicularis Sars, 1865.

Polycope sp. 

Plate 1, figure 13

Discussion. A single specimen representing the 

Cladocopina, a group that is known only rarely as 

fossils, was found in the material studied. Unfortunately it was lost during mounting for photography. 

The specimen measured about 843 (JL in diameter.

REFERENCES CITED

Asano, Kiyoshi, 1939, Limestones of the South Sea Islands 

under the Japanese Mandate: Yabe Jubilee Pub., v. 1, 

p. 537-550.

Benson, R. H., 1969, Preliminary report on the study of abTTssal ostracodes, in Neale, J. W., ed., The taxonomy, morphology, and ecology of Recent Ostracoda: Edinburgh, 

Scotland, Oliver and Boyd, p. 475-478.

Brady, G. S., 1880, Report on the Ostracoda dredged by H.M.S. 

Challenger during the years 1873-1876: Rep. sci. resrlts 

voyage H.M.S. Challenger, Zoology, v. 1, pt. 3, p. 1-184.

Chapman, Frederick, 1910, On the Foraminifera and Ostracoda from soundings (chiefly deep water) collected 

around Funafuti by H.M.S. Penguin: Linnean S'oc. 

London Jour., v. 30 (1907-10), no. 202, p. 388-444.

Cole, W. S., 1950, Larger Foraminifera from the Palau 

Islands: U.S. Geol. Survey Prof. Paper 221-B, p. 21-31.

 1957a, Larger Foraminifera, in Part 3, Paleontology, 

of Geology of Saipan, Mariana Islands: U.S. Geol. Surrey 

Prof. Paper 280-1, p. 321-360.

 1957b, Larger Foraminifera from Eniwetok Atoll drill 

holes: U.S. Geol. Survey Prof. Paper 260-V, p. 743-784 

[1959]. 

-1960, Upper Eocene and Oligocene larger Foraminifera

from Vitu Levu, Fiji: U.S. Geol. Survey Prof. Paper 

374-A, 7 p. [1961].

Guest, N. J., 1959, Geological mapping, Tonga: Fiji Geol. 

Survey Dept., Ann. Rept. for 1958, Council Paper 17, p. 3.

Hoffmeister, J. E., 1932, Geology of Eua, Tonga: Bernice P. 

Bishop Mus. Bull. 96, 93 p.

Hornibrook, N. de B., 1952, Tertiary and Recent marine 

Ostracoda of New Zealand: New Zealand Geol. Surrey 

Palaeont. Bull. 18, 82 p.

 1953, Some New Zealand Tertiary marine Ostraoda 

useful in stratigraphy: Royal Soc. New Zealand Trans., 

v. 81, p. 303-311.

Haddocks, R. F., 1969, Revision of Recent Bairdiidae (Ostracoda) : U.S. Natl. Mus. Bull. 295, 126 p.

Morkhoven, F. P. C. M. van, 1963, Post-Paleozoic Ostracoda, 

their morphology, taxonomy, and economic use: Amsterdam, The Netherlands, Elsevier Pub. Co., v. 2 (generic 

descriptions), 478 p.

Pokorny, Vladimir, 1968, Havanardia g. nov., a new genus of 

the Bairdiidae (Ostracoda, Crust.): [Czechoslovakia] 

ttstfed. Ustav. Geol. Vestnik, v. 43, pt. 1, p. 60-63.

Todd, Ruth, 1970, Smaller Foraminifera of late Eocene age 

from Eua, Tonga: U.S. Geol. Survey Prof. Paper 640-A, 

23 p.

INDEX

[Italic page numbers indicate major references and descriptions]

Page 

algicola, Paranesidea ....._ ..._._________ D8

Annelids ..._________.___________ V 

aquaplanus, Nephokirkos _________.._ 4 

arata, Cytbere ............_...._.__._...._.____ 3

A rgUloecia .............. . ....... ......^....... ......... 9

cylindrica ....... ._..._....._____......___ 9

sp _.______.__ ..__._...._..___..__.._..____...2, 9; pi. 5

Bairdia fortificata ............____

Bai rdiacea ...__.._..______.. 

Bairdiidae _-..._._. _-______

Bairdiinae _.._______._-_ _ 

Bairdiocopina ____________ 

Barnacles ._..._._._.._____.....

bicarinata, Cythereis ________

bispinata, Bythocytheremorpha 

Brachipods ._.._._._-____._ 

Bradleya ....._._._____.____~

tongaensis _..___._____ _1, 2, S; pis 

Bryozoans ______________________

Bythocyp ridinae _ __ _.___________

Bythocypris ...........___________._____ 

proreniformis ___._.____1, 2, 7; pis 

reniformis ___ ___._______________

vainganaensis ... ____._.1, 2, 6; pis. 

Bythocythere _._ _._________.______

turgida .........._________________

sp .____________ -_1, 2, 4; pis, 

Bythocytheremorpha ____._.__ ___.___

bispinata _ _._ ___________ 

montuosa _....._._. .... . .__ 

pacifica .........._ __._._1, 2, 4', Pis

trituberculata ..............................._____

tuber culata ___________-______ 

Bythocytheridae __________________ 

Bythocytherinae - - - 

- 6

- 6 

..2,8 

.. 6 

.. V 

_ 4 

5 

II, V

-1,S 

..1,3 

.1,3 

.. V 

.2,6

-1,6 

,2,5

-6,7 

2,5

-1,4 

.. 4 

2,4

-1,4 

_ 5 

_ 5 

.2,3 

_ 5 

..1,5

- 4

-2,4

Cladocopina ......__.___..______._____

Cletocythereis .........__ ._._._._______

contorta, Cythere .................................

Corals _._________________ 

C rinoi ds _____ _ -________

cylindrica, Argilloecia _________

Cypridacea ____. _____... .. ..

Cyprididae _____-_______- 

Cytheracea ._ - - - 

Cythere arata ....... .._ _._._ .

contorta __.___.________ 

latissima ......... -....__._____ -

limbata .........._._. ..__ _

ininna ___________________

...._.. 2

Cythereis bicarinata _____ 

Cytherella ______._._____

sp ______________. 

Cytherellidae __.______ 

Cytherellinae ____ _-_ 

Gytherina ovata ....._______

umbonata ________-

Cytherocopina _._ .

....._.....________ 6 

____________ 5

_._..._._._.._ 6

._._.___.____..._.__._ 4

._._._._.__ 9

_......_.._2, 9; pis. 2, 5

Cytheropterinae ______________ ... 

Cytheropteron ........~~ ___________

sp. 1 ____________._-___._2, 5; pis.

sp. 2 ____ .__ _______2, 5', pis.

sp. 3 ._. ____ -____._2, 5; pis.

. 2

. 5 

2,3 

2,3 

2,3

Cytheropteron sp. 4 .

Page 

-D2, 5; pi. 3

Cytheruridae _._.._ ._____._._______ 5

Decapod crustaceans __......___..________ V

depressa, Paracytheridea ...._._________ 5

dictyon, Bradleya ...................................._______....!, 3

dimorpha, Macrocypris ........................1, 2, 6', pl.5

Discoasters __.__.___________....__ V

dispar, Paradoxostoma . _.___________ 6

Echinoids ___________..______._._. V

elongata, Krithe ........._......._____.___.....____ 5

Eua, geology of _._________._._____. Ill

relation to Tonga Trench .________ in

Foreword, by H. S. Ladd ______

fortificata, Bairdia _.__..._____

fracticorallicola, Paranesidea ___

Globigerina gortanii zone ____

III

..._ 8

hanuamaensis, Neonesidea _____._____ 8

Havanardia havanensis _._.____._____ 8

sp _...__________.________2, 8; pi. 4

havanensis, Havanardia ..._......___._______ 8

Hemicytheridae _____.____.___._._ 2 

Hemicytherinae ....________.._____._.2, 4

Hermanites ..........____________________ 2

hispida, Paracytheridea ___._____________. 5

Hydrozoans ________________._____ V

Introduction _________._._.._____.._..__

Jugosocythereis __ ...._..._..... _._..__1, 2, 4 

sp ._.._._._...._..._____.__2, 4; pis. 1, 3

kondoi, Tongacythere ____

Krithe ........................_.__

elongata __________

sp ____________.

Krithidae _ __.__._.__

.____1, 2, S; pis. 1, 3 

_____________ 5

..._____.__... 5 

______.2, 5; pi. 3

____________ 5

Krithinae ____________________.___._.___2, 5

Ladd, H. S., Foreword __. 

latissima, Cythere _____. 

limbata, Cythere _______

Pokornyella ..____.__

.... 5

.._ 4

__ 4

Macrocyprididae _____

Macrocypridinae _____._._.

Macrocypris ..........____._._.

dimorpha __________.

parva -_____________

sp _____________

minna, Cythere ..............___.._.

Mollusks __... ._._._.

_.l, 2, 6; pi. 5 

_______ 6

.______....._._1, 2, 6; pis. 2, 4

.__________________ 6

.._...._.____ V

montuosa, Bythocytheremorpha ________ 5

Myodocopida ________.________ 9

Neonesidea ...............~~_____________1, 2, 8

hanuamaensis __________________ 8 

sp. 1 __.._________.______2, 8', pis. 2, 4

sp. 2 _... ___...____..__2, 8; pis. 2, 4 

sp. 3 .______________2, 8; pis. 2, 4 

sp. 4 ___.__._._____._..__2, 8; pis. 2, 4 

sp. 5 __.___._____.___2, 8; pis. 2, 4

Nephokirkos ___..__.______________ 4

Nephokirkos aquaplanus ........... _____ D4 

____2. 4

orbicularis, Polycope _______________ 9

Ostracodes ____________________ V 

Otoliths ..____._______._____..______ V

ovata, Cytherina __.______________ 9

pacifica, Bythocytheremorpha _1, 2, 4', pis. 2, 

Paleoenvironment _________________

Paracytheridea _______________1, 2,

depressa _____._______________ 

hispida _____________________________

sp ______________.____.2, 5; pis. 2,

Paracytherideididae ________________

Paracytherideidinae _______________ 

Paradoxostoma ___________________1, 2.

dispar _____________________ 6

sp __________________2, 6', pis. 2. 5

Paradoxostomatidae ___.__..________ 6

Paradoxostomatinae ...._____________2, 6

Paranesidea .____ ___________1, 2. 8

alfficola ______________________ 8 

fracticorallicola ____________________ 8

8 

4 

4 

4 

6 

V 

9

sp. l _________________2, 8; pi

sp. 2 ...______________.2, 8; pis. 2

sp. 3 __._.___.____._._2, 8; pis. 2 

parva, Macrocypris ..........._______ ._

Plant microfossils 

Platycopida ..........

Podocopida _._. 

Pokornyella _

limbata _

sp ____ 

Polycope ___...

orbicularis

sp ._____

_____2. 4; Pis. 1,

....1, 2, 4

_____ 4 

3 

9 

9

Polycopidae ___ ________________ 

Poly cop inae _____-___.____________

Pontocypridinae 2 

proreniformis, Bythocypris .._.1, 2, 7; pis. 2,

reniformis, Bythocypris ...___________6. 7

schultzi, Triebelina ...... ..__._.. 8

SclerochUus .__________________1, 2, 6

sp ___._________________2, 6; pi, 5

Shark teeth _____________.._____ V

spongicola, Paranesidea _______________ 8

Stearns, H. T., quoted _____________ III

._______1, _ 

1, 2, S; pis. 1, 3 

1,3

Tele-a-hiva __________.__________ 111 

Thaerocythere ___________________ 1 

Thaerocytherinae _.._______________ 2 

Tongacythere _.______ 

kondoi __________ 

tongaensis, Bradleya ____ 

Triebelina schultzi _______________ 8 

trituberculata, Bythocytheremorpha _____ 5 

tuberculata, Bythocytheremorpha _.____1, 5 

turgida, Bythocythere ___._____.____ 4

umbonata, Cytherina ______________ 4 

vainganaeneis, Bythocypris __.__.1, 2, 6; pis. 2, 5

Dll

PLATES 1-5

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

[All figures, except 13, 15, 16, 18, 19, 21, approximately X 45]

FIGURES 1, 2. Jugosocythereis sp. (p. D4).

1. Lateral view, carapace, female. USNM 651483.

2. Lateral view, left valve, male. USNM 651482. 

3. Pokornyella sp. (p. D4).

Lateral view, carapace, female. USNM 651484. 

4, 5. N' ephokirkosl sp. (p. D4).

4. Lateral view, carapace. USNM 651486.

5. Dorsal view, carapace. USNM 651486. 

6-9, 18, 19. Tongacythere kondoi n. gen. n. sp. (p. D3).

6. Lateral view, left valve, holotype. USNM 651466.

7. Ventral view, carapace. USNM 651470.

8. Lateral view, right valve. USNM 651469.

9. Dorsal view, carapace. USNM 651470.

18. Posterior part, left valve. USNM 651467, X 125.

19. Anterior part, left valve. USNM 651467, X 125. 

10-12, 14-17, 20, 21. Bradleya tongaensis n. sp. (p. D3).

10. Ventral view, carapace, male. USNM 651478.

11. Lateral view, left valve, penultimate juvenile. USNM 651475.

12. Dorsal view, carapace, male. USNM 651478.

14. Lateral view, left valve, holotype, female. USNM 651472.

15. Dorsal view, anterior part, right valve, male. USNM 651476. X 125.

16. Dorsal view, posterior part, right valve, male. USNM 651476. X 125.

17. Lateral view, right valve, female. USNM 651477.

20. Lateral view, left valve, female. USNM 651474.

21. Oil-emersion photograph of top of riblet showing micro-ornamentation.

USNM 651473, X 600. 

13. Polycope sp. (p. D9).

Lateral view, carapace. X 85. Specimen lost during photography.
GEOLOGICAL SURVEY PEOFESSIONAL PAPEE 640-D PLATE 1

JUGOSOCYTHEREIS, POKORNYELLA, NEPHOKIRKOS1, 

TONGACYTHERE, BRADLEY A, AND POLYCOPE
PLATE 2

[All figures approximately X 45]

FIGURE 1. Cytheropteron sp. 1 (p. D5).

Lateral view, left valve. USNM 651497. 

2. Paracytheridea sp. (p. D5).

Lateral view, right valve. USNM 651498. 

3, 6, 12-14, 16. Bythocytheremorpha pacifica n. sp. (p. D4).

3. Lateral view, right valve. USNM 651494. 

6. Lateral view, left valve, USNM 651493.

12. Ventral view, right valve. USNM 651491.

13. Dorsal view, right valve. USNM 651492.

14. Lateral view, left valve, holotype. USNM 651490. 

16. Lateral view, right valve. USNM 651491.

4. Bythocypris vainganaensis n. sp. (p. D6).

Lateral view, carapace. USNM 651448.

5. Paradoxostoma sp. (p. D6).

Lateral view, carapace. USNM 651501.

7. Cytheropteron sp. 2 (p. D5).

Lateral view, right valve. USNM 651496.

8. Neonesidea sp. 1 (p. D8).

Lateral view, carapace. USNM 651461. 

9, 10. Paranesidea sp. 2 (p. D8).

9. Lateral view, carapace. USNM 651456. 

10. Lateral view, carapace. USNM 651457. 

11. Cytheropteron sp. 3 (p. D5).

Lateral view, carapace. USNM 651502. 

15, 19. Macrocypris sp. (p. D6).

15. Lateral view, carapace. USNM 651445. 

19. Lateral view, carapace. USNM 651443.

17. Neonesidea sp. 4 (p. D8).

Lateral view, carapace. USNM 651463.

18. Bythocythere sp. (p. D4).

Lateral view, right valve. USNM 651488.

20. Cytherella sp. (p. D9).

Lateral view, right valve. USNM 651438.

21. "Neonesidea" sp. 5 (p. D8).

Lateral view, carapace. USNM 651460.

22. Bythocypris proreniformis n. sp. (p. D7).

Lateral view, carapace, holotype. USNM 651449.

23. Neonesidea sp. 2 (p. D8).

Lateral view, carapace. USNM 651458.

24. Neonesidea sp. 3 (p. D8).

Lateral view, juvenile carapace. USNM 651454.

25. Paranesideal sp. 3 (p. D8).

Lateral view, carapace. USNM 651452.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 640-D PLATE 2

CYTHEROPTERON, PARACYTHERIDEA, BYTHOCYTHEREMORPHA, BYTHOCYPRIS, 

PARADOXOSTOMA, NEONESIDEA, PARANESIDEA, MACROCYPRIS, BYTHOCYTHERE, 

CYTHERELLA, "NEONESIDEA," AND PARANESIDEA?
PLATE 3

FIGURES 1, 5. Cytheropteron sp. 2 (p. D5).

1. Interior view, right valve. USNM 651496.

5. Dorsal view, right valve. USNM 651496.

2. Nephokirkosl sp. (p. D4).

Dorsal view, carapace. USNM 651486.

3. Cytheropteron sp. 3 (p. D5).

Dorsal view, carapace. USNM 651502.

4. Paracytheridea sp. (p. D5).

Dorsal view, right valve. USNM 651498. 

6, 7, 17, 18. Bythocytheremorpha pacifica n. sp. (p. D4).

6. Dorsal view, right valve. USNM 651491.

7. Dorsal view, left valve, holotype. USNM 651490.

17. Interior view, left valve. USNM 651491.

18. Interior view, right valve, holotype. USNM 651490.

8. 10. Cytheropteron sp. 1 (p. D5).

8. Dorsal view, left valve. USNM 651497.

10. Interior view, left valve. USNM 651497.

9. 11. Cytheropteron sp. 4 (p. D5).

9. Dorsal view, left valve. USNM 651495.

11. Interior view, left valve. USNM 651495. 

12, 13, 20. Tongacythere kondoi n. sp. (p. D3).

12. Dorsal view, left valve. USNM 651468.

13. Dorsal view, right valve. USNM 651471. 

20. Interior view, left valve. USNM 651468. 

14, 15. Jugosocythereis sp. (p. D4).

14. Dorsal view, left valve. USNM 651485.

15. Dorsal view, carapace. USNM 651483. 

16. Pokornyella sp. (p. D4).

Dorsal view, carapace. USNM 651484. 

19. Krithe sp. (p. D5).

Interior view, left valve. USNM 651503. 

21. Bradleya tongaensis n. sp. (p. D3).

Interior view, right valve, male. USNM 651479.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 640-D PLATES 

t

CYTHEROPTERON, NEPHOKIRKOSf, PARACYTHERIDEA,BYTHOCYTHEREMORPHA, 

TONGACYTHERE, JUGOSOCYTHEREIS, POKORNYELLA, KRITHE, AND BRADLEY A
PLATE 4

FIGURES 1, 3. Bythocythere sp. (p. D4).

1. Dorsal view, left valve. USNM 651489.

3. Interior view, left valve. USNM 651487. 

2, 9. Paranesidea sp. 2 (p. D8).

2. Anterior view, carapace. USNM 651457.

9. Dorsal view, carapace. USNM 651457. 

4, 5. "Neonesidea" sp. 5 (p. D8).

4. Anterior view, carapace. USNM 651464.

5. Dorsal view, carapace. USNM 651464. 

6, 14. Neonesidea sp. 1 (p. D8).

6. Anterior view, carapace. USNM 651461. 

14. Dorsal view, carapace. USNM 651461. 

7, 8. Neonesidea sp. 2 (p. D8).

7. Dorsal view, carapace. USNM 651459.

8. Anterior view, carapace. USNM 651459. 

10. Macrocypris sp. (p. D6).

Dorsal view, carapace. USNM 651444. 

11, 12. Neonesidea sp. 4 (p. D8).

11. Dorsal view, carapace. USNM 651462.

12. Anterior view, carapace. USNM 651462. 

13, 16. Paranesideat sp. 3 (p. D8).

13. Anterior view, carapace. USNM 651453. 

16. Dorsal view, carapace. USNM 651453. 

15, 22, 23. Havanardia sp. (p. D8).

15. Dorsal view, left valve. USNM 651451.

22. Interior view, left valve. USNM 651451.

23. Lateral view, left valve. USNM 651451. 

17, 18. Neonesidea sp. 3 (p. D8).

17. Anterior view, carapace. USNM 651455.

18. Dorsal view, carapace. USNM 651455. 

19-21. Paranesidea sp. 1 (p. D8).

19. Dorsal view, carapace. USNM 651465.

20. Right lateral view, carapace. USNM 651465.

21. Anterior view, carapace. USNM 651465.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 640-D PLATE 4

20 21

BYTHOCYTHERE, PARANESIDEA, "NEONESIDEA," NEONESIDEA, 

MACROCYPRIS, PARANESIDEA?, AND HAVANARDIA
PLATE 5

FIGURES 1, 2, 7. Cytherella sp. (p. D9).

1. Interior view, left valve. USNM 651439.

2. Interior view, right valve. USNM 651440. 

7. Dorsal view, right valve. USNM 651440. 

3, 4, 9, 10. Bythocypris vainganaensis n. sp. (p. D6).

3. Lateral view, carapace, holotype. USNM 651446.

4. Interior view, left valve. USNM 651447.

9. Anterior view, carapace, holotype. USNM 651446.

10. Dorsal view, carapace, holotype. USNM 651446. 

5, 6. Argilloecia sp. (p. D9).

5. Interior view, right valve. USNM 651480.

6. Dorsal view, right valve. USNM 651481. 

8, 11, 13, 17, 19. Macrocyprisl dimorpha n. sp. (p. D6).

8. Lateral view, male carapace. USNM 651441.

11. Lateral view, female carapace, holotype. USNM 651442. 

13. Dorsal view, male carapace. USNM 651441. 

17. Anterior view, female carapace, holotype. USNM 651442. 

19. Dorsal view, female carapace, holotype. USNM 651442. 

12, 15, 18. Bythocypris proreniformis n. sp. (p. D7).

12. Anterior view, carapace. USNM 651450. 

15. Dorsal view, carapace. USNM 651450. 

18. Lateral view, carapace. USNM 651450. 

14. Paradoxostoma sp. (p. D6).

Dorsal view, carapace. USNM 651501. 

16. Sclerochilus sp. (p. D6).

Lateral view, left valve. USNM 651499.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 640-D PLATE 5

IOO/*

IOO/<

CYTHERELLA, BYTHOCYPRIS, ARGILLOECIA, 

MACROCYPRIS1, PARADOXOSTOMA, AND SCLEROCHILUS