Recent Foraminifera of the Marshall Islands Bikini and Nearby Atolls, Part 2, Oceanography (Biologic) GEOLOGICAL SURVEY PROFESSIONAL PAPER 260-H ERRATA SLIP FOR PROFESSIONAL PAPER 260-H In the distribution tables (1-5) italic numbers indicate abundance of the species in percentages of the Foraminifera present in the sample. Arabic numbers indicate actual count of specimens. Recent Foraminifera of the Marshall Islands By JOSEPH A. CUSHMAN, RUTH TODD, and RITA J. POST Bikini and Nearby Atolls, Part 2, Oceanography (Biologic) GEOLOGICAL SURVEY PROFESSIONAL PAPER 260-H UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1954 UNITED STATES DEPARTMENT OF THE INTERIOR Douglas McKay, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price $1.75 (paper cover) CONTENTS Page Page ______.____-_-__-____-___-.-..______.____ 319 Systematic descriptions—Continued Introduction- ______---_-____--__-__-_-____-____--__ 319 Trochamminidae. _______________________________ 342 General features_____----------_--_-_-__-________^__ 319 Lagenidae _____________________________________ 342 Fauna of reef flats.__.--________-_-___._________ 319 Polymorphinidae_ ________-_-_-_----_--_-_-_-_-_ 344 Fauna of lagoons_______________________________ 320 Nonionidae_ __-__________________---_-----_---_ 345 Fauna of outer slopes. __.-_.____-_-_. ___________ 321 Camerinidae ___________________________________ 346 Fauna of deep water. ___________________________ 321 Peneroplidae___________________________________ 348 Sylvania Guyot core.______________^___-____ 322 Alveolinellidae________________________________ 348 Species restricted to guyot-__.___-_-.-_______ 322 Heterohelicidae- ________________________________ 349 Nondiagnostic species._________----_-__^________ 323 Buliminidae_- _ _________-_______-_-__--_--___--_ 349 Notes on distribution by families. __-.__._._._____ 325 Ellipsoidinidae____________-_____--_____-_----__ 356 Localities and depths of samples...__.-___^_-_________ 326 Rotaliidae. ___-----__----_---_--------------__- 356 Rongerik Lagoon ________._._________^________._ 326 Pegidiidae._--__-____-------------------___-___ 361 Rongelap Atoll__----_--__-___-_-___---.--______ 326 Amphisteginidae- _______________________________ 362 Bikini Atoll____---_-___-_-_-____-_-__-___-_-_-_ 326 Calcarinidae.__________________________________ 363 Eniwetok Lagoon____________-__________________ 327 Cymbaloporidae. _____-___-__--_-______-__---___ 364 Outer slopes of Eniwetok Atoll___________________ 328 Cassidulinidae_ _ ___-----_--_-_---_----_______. 365 Systematic descriptions-.-__-_--__-____-_-_-____-__-_ 328 Chilostomellidae- _______-______-_.-___---_______ 367 Saccamminidae- _---_-_--_____-___-_-_--_____-_- 328 Globigerinidae________-_-_-_-_-___-__--_______ 368 Hyperamminidae. __--___--_________-_-_________ 328 Globorotaliidae_ _ _______________________________ 370 Ammodiscidae. _ _--------_-___-_---___-_________ 328 Anomalinidae. __________--______--___-__-__--__ 370 Textulariidae__-_______--_________.___-____._. 328 Planorbulinidae. _ __------___--__-_-___________ 372 Verneuilinidae- _________________________________ 330 Rupertiidae---------------------------_-----_-_ 373 Valvulinidae._-------_-_--__-__-_-___-_-_._____ 331 Homotremidae -__________-___-__---_-__-_______ 373 Miliolidae_____--_---_-__--__________.________ 332 Bibliography _-_______-________-__-_--_---________._ 374 Ophthalmidiidae-- _ _____________________________ 341 Index..-_------_-_--_-_---_-_----_-_--__--_.______ 379 ILLUSTRATIONS [Plates 82-93 follow page 384 PLATE 82. Miscellaneous large specimens of Foraminifera from families Verneuilinidae to Homotremidae. 83. Saccamminidae, Textulariidae, Verneuilinidae, Valvulinidae, Miliolidae. 84. Miliolidae. 85. Miliolidae, Ophthalmidiidae, Trochamminidae. 86. Lagenidae, Polymorphinidae, Nonionidae. 87. Camerinidae, Peneroplidae, Alveolinellidae, Heterohelicidae, Buliminidae. 88. Buliminidae, Ellipsoidinidae, Rotaliidae. 89. Rotaliidae, Pegidiidae. 90. Amphisteginidae, Calcarinidae, Cymbaloporidae, Cassidulinidae, Chilostomellidae. 91. Globigerinidae, Globorotaliidae, Anomalinidae, Planorbulinidae, Rupertiidae. 92. Galcarinidae and Homotremidae. 93. Homotremidae. Page FIGURE 116. Composition of typical beach sample. _ ...______________-l__._._.___ ____________________ 325 117. Composition of typical lagoon sample_----_-__-_-_______-_-__---_-----__-___-_--_--____- 325 118. Composition of typical deep-water sample.__--_________-_____________--_-___-_---__-___- 326 nx IV CONTENTS TABLES Page TABLE 1. Distribution of Saccarnminidae, Hyperamminidae, Ammodiscidae, Textulariidae, Verneuilinidae, Valvulinida^, and Miliolidae in the Marshall Islands_-__________________________________________________________-__ Facing 338 2. Distribution of Miliolidae, Ophthalmidiidae, Trochamminidae, Lagenidae, Poty morphinidae, and Nonionidae in the Marshall Islands.__________________________________________________________________________ Facing 346 3. Distribution of Camerinidae, Peneroplidae, Alveolinellidae, Heterohelicidae, Buliminidae, and Ellipsoidiniiae in the Marshall Islands. __________________________________________________________________________ Facing 354 4. Distribution of Rotaliidae, Pegidiidae, Amphisteginidae, Calcarinidae, Cymbaloporidae, Gassidulinidae, and Chilostomellidae in the Marshall Islarids_--_______-___--__________--____-__-__-___-___-____----__- Facing 362 5. Distribution of Globigerinidae, Globorotaliidae, Anomalinidae, Planorbulinidae, Rupertiidae, and Homotremidae iti the Marshall Islands___________________________________________________________________ Facing 370 BIKINI AND NEARBY ATOLLS, MARSHALL ISLANDS RECENT FORAMINIFERA OF THE MARSHALL ISLANDS By Joseph A. Cushman,1 Ruth Todd, and Rita J. Post ABSTRACT among themselves, but there are notable differences This paper records 331 species and varieties, most of which are between these atolls and certain other Pacific islands; formally described and illustrated, from 195 samples from the for example, the absence of Baculogypsina and vr.rious lagoons and outer slopes of the Marshall Islands: Rongerik, medium to large species of Rotalia, such as E. calcar Rongelap, Bikini and Eniwetok. Seventeen species and two (D'Orbigny), and the great variety of the miliolids. varieties are new and 33 are undeterminable specifically. The samples range in depth from the beach to 835 fathoms on The percentages recorded hi the distribution table Sylvania Guyot adjoining Bikini Atoll. Tables showing the were estimated by means of a picking tray divided into distribution and abundance (as percentage of the total) of all segments to facilitate the counting of all specimen? in a the species in each sample are included. Species are listed unit area of a thinly scattered sample. Depending according to their ecologic significance or lack of it. Depth, upon the variety of forms present, fifty to several and access to the open ocean, appear to be the chief ecologic factors affecting distribution and abundance. hundred specimens were counted in each sample. In. the original picking of the samples the species were INTRODUCTION picked quantitatively up to 25 specimens. Beyond that point, percentages were estimated, but where the A series of bottom foraminiferal samples from four percentages are low the estimates are very rough. coral atolls at the northwestern end of the Marshall In most cases the samples were treated with carbon group in the south Pacific has been studied both as to tetrachloride to separate the smaller species from the the total fauna present and as to the relative abundance larger and heavier tests of Cakarina, Amphistegina, of the species at various depths and positions within the Hezerostegina, Marginopora, etc., and from the frag­ lagoon and on the outer slopes of the atoll. ments of coral, shell, and Halimeda, but both fractions The samples available give a rather complete picture were studied. of the foraminiferal faunas present in the waters of and The most abundant single species in nearly all the surrounding the atolls. The faunas may be divided as lagoon samples (exclusive of beach samples) is Amphis­ follows: reef flat and lagoon beach fauna, lagoon and tegina madagawarientiis D'Orbigny, but its varying shallow outer slope fauna, and deep- water fauna (chiefly percentages are not so much significant of changes in a planktonic fauna with the addition of rare benthonic its abundance as a reflection of the richness or barren­ species). In each case the faunas may intergrade, or ness of the accompanying fauna. dominant species from either of the first two may work We appreciate the many helpful suggestions received down the slope into the second or third and obscure during discussions of our work with Miss Frances L. its normal appearance. Parker of Scripps Institution of Oceanography, Dr. W. Generally speaking, the faunas here studied are Storrs Cole of Cornell University, Drs. Harry S. Ladd characteristic of the tropical Pacific. About 84 percent and Joshua I. Tracey of the U. S. Geological Survey of the species are identified with known species from the and Dr. Kenneth O. Emery of the University of South­ tropical Pacific. About 6 percent of the species and va­ ern California. rieties found seem to be new to science, and 10 percent are undeterminable specifically and may also be new. GENERAL FEATURES The faunas of the four atolls do not differ significantly FAUNA OF BEEF FLATS 1 Dr.