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Chapter 64. Evolution and biogeography of Orionina in the Atlantic, Pacific and Caribbean : Evolution and speciation in Ostracoda, II
928 T. M.
After its original description based on species from Florida by Puri (1953), Bold (1963) redescribed Orionina in detail, giving a comprehensive list of occurrences from the Caribbean and
Central America. The type species, 0. vaughani was described in 1904 by Ulrich and Bassler based
on material from the Pliocene of Virginia. Although our results and interpretations of some of
the relationships among species differ slightly from those of van den Bold, his work stands as the
underlying framework for all subsequent study of this genus. Gunther and Swain (1976) provided
important occurrence data from the Gulf of Panama and postulated some evolutionary
relationships in Orionina. Other important occurrences of Orionina from the eastern Pacific are
found in Swain (1967, 1969), Swain and Gilby (1967), and Valentine (1976). Holden (1976)
described Orionina flabellacosta from the Miocene of Midway Island, Hawaii. A new species
closely related to Holden's species is proposed below.
LENGTH vs. HEIGHT in OR/O/U/NA
1-Plot of carapace length versus height for Orioninu from various localities. The vuughuni group,
designated by squares, includes specimens assigned by other authors to 0. pseudovuughani and 0 .
serruluta. Holotype specimens are indicated by open stars (measurements of 0. brudyi, 0. sirnilis, 0.
serrulatu, and 0. vuughuni holotypes are taken from Bold, 1963).
Evofution and Biogeography of Orionina 929
LENGTH vs. RIDGE ANGLE in OR/ON/NA
TEXT-FIo.2-Plot of carapace length versus angle between median longitudinal ridge and oblique ridge in
posterior part of the carapace. See Text-fig. 1 for explanation of symbols.
Table 1 lists the formations and recent material from which specimens of Orionina were exPoag. 1972 and 0. butlerae Bold. 1965 were not examined, nor was 0.fragilis Bold, 1963. One hundred and sixty one specimens from our collection
amined Pre-late Miocene snecies 0.armata
-I-^* ----- L - 1
taken of carapace length, anterior and posterior height, and distance from the anterior margin to
the muscle platform. We also measured the angle between the median longitudinal ridge and the
oblique ridge (see Text-fig. 2). These data were subjectedto various bivariate analyses of which two
plots are presented here.
Table 2 lists the fourteen proposed species of Orionina and the taxonomic assignment given in
the present paper. We recognize ten species including the three unstudied species 0. armata, 0.
930 T. M. CRONINAND N. SCHMIDT
Cueva de Angostura
Acklins Island, Bahamas
St. Thomas, U.S. Virgin Islands
Dominican Republic, North Shore
Dominican Republic, South Shore
Payardi Island, Panama
Gulf of Panama
Campeche Banks, Mexico
Corinto Bay, Nicaragua
t, Exact locality information is available from T. M. Cronin.
SPECIES OF OriOnina.
t 0, armata Poag, 1972
Cythere bermudae Brady, 1880
0 . bradyi van den Bold, 1963
0. brouwersae new species
t 0 . butlerae van den Bold, 1965
0. ebanksi Teeter, 1975
0. eruga van den Bold, 1963
0. flabellacosta Holden, 1976
t 0. fragilis van den Bold, 1963
0. boldi new species
0 .pseudovaughani Swain, 1967
Cythereis reticulata Hartmann, 1956
Cythere serrulata Brady, 1869
0 . similis van den Bold, 1963
Cythere vaughani Ulrich and Bassler, I904
t, Not Studied.
0 . armata
0 . bradyi
0 . bradyi
0 . brouwersae n. sp.
0 . butlerae
0 . eruga
0 . boldi n. sp.
0 . vaughani
0 . vaughani
0 . similis?
0 . vaughani
fragilis, and 0 . butlerae, and the seven studied for this paper-0. boldi, 0. bradyi, 0 .brouwersae,
0 . ebanksi, 0 . eruga, 0 . flabellacosta, and 0 . vaughani. Each species consists of populations
having a distinct morphotype consistently distinguishable from the other species in populations
examined from most of their stratigraphical and geographical ranges. Plate 1 illustrates the seven
Evolution and Biogeography of Orionina 931
species and Text-fig. 1 plots their carapace lengths and heights. These figures should be referred
to in the following summaries of the characteristics of each species.
Orionina vaughani is comprised of a complex of populations all having relatively large carapaces, strong sexual dimorphism, well-developed ridges and surface reticulation, and, in some
populations, variable radial pore patterns. The intraspecific variation and synonymy of 0. vaughani
with other species is discussed below. 0. bradyi has a small carapace, lacks the vertical posterior
ridge present in other species, and has a low angle between the medial and oblique ridges (see P1. 1,
fig. 1). Sexual dimorphism is not as pronounced as in other species of Orionina. 0. eruga displays
a very large, elongate carapace, a strongly convex dorsum and less-tapered posterior end. The
murae forming the reticulum are not as sharp as in 0. vaughani. 0. ebanksi is very similar to 0.
bradyi, especially in its small size and evenly reticulate ornamentation. It differs in having its dorsal
ridge merge gradually with the dorsum in contrast to the sharper intersection in 0. bradyi and in
the curved shape of the dorsal margin. 0. brouwersae is quite distinct from other members of the
genus and is characterized by a very high carapace (Text-fig. 1) and a distinct pattern of longitudinal
ridges. Also, the anterior ridge runs through the eyespot continuing to the dorsal margin in contrast to the ridge position in other species, 0.flabellacosta lacks the prominent medial and vertical
ridges typical of Caribbean and Atlantic Orionina, but has the characteristic curved ventral ridge
and reticulate surface. Gunther and Swain (1976) illustrated a large, strongly calcified species, which
they designated as Orionina n. sp. 2, from the Gulf of Panama. We have found this form in the
Pliocene of Costa Rica, and in modern sediments off the Florida Keys. We describe this new species as 0. boldi below.
We gave considerable attention to the relationships between Orionina vaughani and the species
0. serrulata, 0. pseudovaughani, and 0 . reticulata, each long recognized as closely related, but
usually separated on the basis of minor differences. Specimens that have been identified as 0.
serrulata are said to be identical to vaughani in external appearance, differing only in the presence of
indentations in the line of concrescence and bundling of radial pores, whereas 0. vaughani has
numerous parallel, straight pores (Bold, 1963). In a preliminary study of Gulf of California
ostracods, Swain et al. (1964) identified 0. vaughani for the first time from the Pacific, but later
Swain (1967) redescribed these populations as 0. pseudovaughani, which he characterized as
differing from 0. vaughani in having three rather than four pillars in the anterior vestibule. Swain
also pointed out that these populations might be conspecific with 0. serrulata, but he considered
0. serrulata to have a confused taxonomic history.
We regard 0. serrulata, 0.pseudovaughani, and 0 .reticulata as conspecific with 0. vaughani and
believe that the minor differences among them represent interpopulational variation, perhaps
related to local environmental conditions. We don’t consider the variation in radial pores a specific
level character because we have observed populations from the Limon of Costa Rica that have
individuals with both the straight, parallel pattern and the bundled pattern. Similarly, Gunther
and Swain (1976) illustrate these two types of pore pattern in populations from the Gulf of
Panama and they assign them to two species (0.vaughani and 0 .pseudovaughani). It is our opinion
that these two morphotypes belong to a single species. Many other shallow marine genera, such
as Proteoconcha (Plusquellec and Sandberg, 1969; Hazel and Cronin, this volume) show strong
variation in radial pores. Text-fig. 1 shows the similarity in carapace length and height of Orionina
populations from the eastern United States, Central America and the Caribbean, the eastern
932 T. M. CRONIN AND N. SCHMIDT
Pacific and Florida. The SEM photographs in Plate 2 show the similarity in surface ornamentation
of populations from different regions. The evidence shows that intraspecific variation is
substantially less than interspecific variation within the genus. Plate 2 illustrates this point with
four specimens of 0. boldi n. sp. This species almost certainly descended from Caribbean
populations of 0. vaughani but the two species are consistently distinct from one another in all the
populations studied. There are no gradational populations between the two species.
The formation of the Isthmus of Panama during the Pliocene, about 3 to 4 million years ago, represents a major barrier to the genetic interchange of eastern Pacific and Caribbean populations
that were formerly contiguous with each other. That Orionina lived on both sides before the Isthmus
developed and was not artifically introduced into the Pacific is demonstrated by Miocene and
early Pliocene occurrences throughout the Caribbean and southeastern North America (Bold,
1963), in the Pacific at Midway Island (Holden, 1976), and reported here for the first time, in
Ecuador and the Marshall Islands. Evidence from the two species known as fossil and/or Holocene
from both sides indicates minor morphological divergence of populations since separation several
million years ago. Orionina vaughani is known pre-and post-Isthmus on both sides and comparison
of specimens illustrated in Plate 2 show a strong morphological similarity between Pacific and
Atlantic/Caribbean forms. 0. bold occurs in Holocene sediments on the Pacific side in the Gulf
of Panama and off southern Florida. As a fossil, it is known from the Pliocene of Costa Rica.
Although much less common than 0. vaughani, there are no consistent differences in carapace
morphology in populations from the different regions (PI. 2).
A second type of barrier isolating shallow water populations is deep water. Deep water separates many populations of Orionina living off Caribbean Islands from shelf populations off the
coasts of the Americas and from each other. However, the distances across these barriers is relatively
small and they were even less during the numerous glacial periods when sea level was 100 to 150
metres lower that its present level. Consequently, there is a much higher probability of passive
dispersal of ostracods (possibly on drifting seaweed, see Teeter, 1973; Cronin, this volume) among
western Atlantic, Caribbean and Gulf of Mexico populations than there is among more distant
islands such as the Hawaiian Islands, the Marshall Islands and off Fiji, where 0. Jabellacosta
and 0. brouwersae occur. In the case of these two Pacific species, alternative hypotheses might
explain the seemingly anomalous occurrence of Orionina, a genus otherwise restricted to the
eastern Pacific, western Atlantic and Caribbean. One alternative is that these species are not phy-
PLATEl-Fig. 1 . Orionina bradyi Bold, 1963. Lateral view, left valve, female (USNM 403818, Holocene, Bahamas),
x 78 Figs. 2, 4. Orionina brouwersae n. sp. 2. Internal view, left valve, female (USNM 403819, Recent, Fiji),
x 78 4. Lateral view, left valve, female (Holotype, USNM 403820, early Miocene-late Pliocene, Marshall
Islands), x 78 Fig. 3. Orionina cf. 0. brouwersae Cronin and Schmidt n. sp. Lateral view, left valve, female
(USNM 403821, early Miocene-late Pliocene, Marshall Islands), x78 Figs. 5, 6, 9, 10. Orionina vaughani
(Ulrich and Bassler, 1904). 5. Lateral view, left valve, female (USNM 403822, Pliocene, Costa Rica), x 78
6. Lateral view, left valve, male (USNM 403823, Pliocene, Costa Rica), x78 9. Lateral view, left valve,
female (USNM 403824, Pliocene, North Carolina), x 7 8 10. Lateral view, left valve, male (USNM 403825,
Pliocene, North Carolina), x78 Figs. 7, 8. Orionina boldi n. sp. 7. Lateral view, left valve, female
(Holotype, USNM 403826, Holocene, Florida), x 78 8. Lateral view, left valve, male (USNM 403827,
Holocene, Gulf of Panama), x 7 8 Figs. 11, 12. Orionina cf. 0. eruga Bold, 1963. 1 1 . Lateral view, left
valve, female (USNM 403831, Pliocene, Venezuela), x 78 12. Lateral view, left valve, male (USNM 403832,
Pliocene, Venezuela), x 78 Fig. 13. Orionina ebanksi Teeter, 1975. Lateral .view, left valve, female (USNM
403833, Holocene, St. Thomas, U. S. Virgin Islands), x78
Evolution and Biogeography of Orionina 935
logenetically related to Caribbean Orionina, but are descended from another western Pacific hemicytherine lineage. At present, well-documented Miocene to Holocene faunas from Midway (Holden,
1976) and the Marshall Islands (Cronin, unpublished data) do not show any likely candidates.
Further, as recognized by Holden, external and internal carapace features are clearly Orioninalike, although these central and western Pacific forms have evolved so that they are distinct from
other species in details of carapace ornament. We consider the most reasonable interpretation to
be that 0. flabellacosta split from early Miocene populations of Orionina that became isolated
in the Hawaiian Islands, and that during the middle or late Miocene, 0. brouwersae split when populations became dispersed farther west in the Marshall Islands. Although the Pacific data are still
sparse and phylogenetic relationships unclear, the evidence indicates at least two speciation events
occurred when relatively small populations became isolated on small islands, probably through
passive dispersal on seaweed (Teeter, 1973). These speciation events contrast with the lack of speciation or even intraspecific morphologic divergence that resulted from isolation by the Isthmus of
The patterns observed in Orionina are, of course, subject to different interpretations. For example,
Gunther and Swain (1 976) hypothesized that major barriers existed between Jamaica and Florida
and between Venezuela and the eastern Pacific such that “three more-or-less isolated evolving
groups” (p. 141) of Orionina can be recognized. Based on our distribution data and the inferred
dispersal capabilities of tropical ostracod genera (see also Teeter, 1973), we do not believe there
were effective barriers east of Central America within the Caribbean, Gulf of Mexico, and western
Atlantic regions. Although 0. ebanksi and 0. boldi probably evolved within this region, there is no
direct evidence for geographic isolation having been the cause. Further, considering the 25 million
year history of the genus, surprisingly few species have evolved. Even the land barrier formed by
the Isthmus of Panama has not yet led to divergence within Orionina. We believe the preliminary
evidence from the central and western Pacific shows isolation of small populations led to the formation of at least two new species and the most significant morphological divergence within the
genus. Overall, the results support the hypothesis of Valentine and Jablonski (1 983) that geographical isolation of large populations of benthic invertebrates results in slow rates of morphological
change. Conversely, rapid morphological change accompanying speciation events occurs when
small populations become isolated.
Our study was designed to investigate the effects of types of geographical isolation on the genus
Orionina. A major taxonomic revision is beyond the scope of this paper. Further, the phylogenetical relationships of some species remain unclear, so an abbreviated systematic section is given.
PLATE2-Figs. 1-10. Orionina vaughani (Ulrich and Bawler, 1904). 1 . Lateral view, left valve, (USNM 403834,
Holocene, Gulf of Panama), x 7 8 2. Lateral view, left valve, (USNM 403835, early Pleistocene, North
Carolina), x 78 3. Lateral view, left valve, (USNM 403836, early Pleistocene, North Carolina), X 78 4.
Lateral view, left valve, (USNM 403837, Holocene, Gulf of Panama), x 78 5 . Lateral view, left valve,
(USNM 403838, middle Pleistocene, South Carolina), x 78 6. Lateral view, left valve, (USNM 403839,
early Pliocene, South Carolina), x 78 7. Lateral view, left valve, (USNM 403840, Miocene, Ecuador),
x 78 8. Lateral view, left valve, (USNM 403841, Pliocene, Panama), x 78 9. Lateral view, left valve,
(USNM 403842, middle Pleistocene, Florida), X 78 10. Lateral view, left valve, (USNM 403843, late
Miocene, Venezuela), x 7 8 Figs. 11-14. Orionina boldi n. sp. 11. Lateral view, left valve, (USNM 403828,
Pliocene, Costa Rica), x 78 12. Lateral view, left valve, (USNM 403829, Pleistocene, Florida), X 78.
13. Lateral view, left valve, (USNM 403827, Holocene, Gulf of Panama), x 7 8 14. Lateral view, left
valve, (USNM 403830, Holocene, Florida Keys), X 78.
936 T. M. CRONIN
AND N. SCHMIDT
Van den Bold (1963) discussed early studies of Orionina and should be consulted for Caribbean
occurrences, synonymies, and detailed descriptions of most species. We concentrate here on the
two new species and their distinction from other Orionina. As mentioned above, we did not examine 0. armata, 0.fragilis and 0. butlerae, but we consider at least the first two as valid species
distinct from those illustrated here. Orionina butlerae we believe to be in need of further study.
BOLDI Cronin and Schmidt n. sp.
(PI. 1, figs. 7, 8; P1. 2, figs. 11-14)
Etymology.-Named for Dr. W. A. van den Bold, Louisiana State University, in honor of his
pioneering work on Orionina.
Types.-Holotype, a female left valve from the Holocene off the Florida Coast, USNM 403826
(PI. 1 , fig. 7). Sample 1554 of Hathaway (1971), 55 m water depth 26”31.1’N, 8Oo01.4’W.
Zl1ustratedspecimens.-USNM 403827 (PI. 1, fig. 8 ; PI. 2, fig. 13); USNM 403828 (PI. 2, fig. 11);
USNM 403829 (PI. 2, fig. 12); USNM 403830 (Pl. 2, fig. 14).
Diagnosis.-Very large and heavily calcified, having very thick longitudinal ridges and two
subvertical ridges in the posterior region that connect the longitudinal ridges.
Description.-Carapace slightly more rectangular and less tapered posteriorly than other Orionina, valve walls very thick and heavily calcified. Lateral surface of valves having two prominent
longitudinal ridges that converge near the muscle node and that diverge anteriorly and posteriorly
from the anterocentral region. Posteriorly, there is a strong nearly vertical ridge and anterior of
this, a distinct oblique ridge connecting the longitudinal ridges. Postero-ventral ridge is sometimes
nodose. Between the ridges the surface is variably reticulate to almost smooth. Internal features
are typical for the genus and there are many straight, parallel, evenly spaced radial pore canals.
Remarks.-Some female specimens resemble large males of 0. vaughani, but differ in their
larger size, and the presence of the well-developed oblique ridge, anterior to the posteroventral
ridge, that connects the longitudinal ridges. Some specimens resembling 0. boldi were found in
the Bowden Formation of Jamica, but they were much smaller and require additional study.
Occurrence.-Recent off South Florida and Gulf of Panama; Bermont Formation, middle
Pleistocene, subsurface of South Florida; Limon Formation, Pliocene, Costa Rica.
(PI. 1, fig. 1)
Remarks.-This widespread species is well-known throughout the Caribbean (Bold, 1963). DiasBrito et al. (this volume) has also found it in Sepetiba Bay, Brazil. Bold (1963, p. 45-47) considers
some specimens described by Brady (1880) as Cythere bermudae to be synonymous with 0. bradyi
and discusses the taxonomy of these species in detail.
BROUWERSAE Cronin and Schmidt n. sp.
(PI. 1, figs. 2,4)
Etymology.-Named for Dr. Elisabeth M. Brouwers, U. S. Geological Survey.
Types.-Holotype, a female carapace, USNM 403820, from the Pliocene (a depth of 498 feet in
a core) from Enewetak Atoll, Marshall Islands (PI. 1, fig. 4).
Illustrated specimens.-USNM 403819 (PI. 1, fig. 2).
Diagnosis.-Relatively low length/height ratio, valve surface evenly reticulate, having two
short parallel anterior ridges, two fine posterior ridges, an anterior marginal ridge running through
the eye tubercle.
Evolution and Biogeography of Orionina 937
Description.-Carapace arched, convex dorsally, evenly rounded anteriorly, surface ornament
consisting of reticulation and polygonal fossae. An anterior marginal ridge runs through eye
tubercle continuing along dorsal margin. Longitudinal ridges differ from those in other Orionina,
consisting of two short anterior ridges, two fine, posterodorsal ridges and a long ventral ridge.
Ridges and murae are relatively thin compared to Caribbean species.
Remarks.-Plate 1, figure 3 shows a morphotype that is tentatively assigned to this species
based on its size shape and reticulate surface. However it clearly differs from the Holotype illustrated in Plate 1, figure 4 in the development and orientation of posterodorsal and to a lesser extent in
the anterocentral ridges. Both these specimens come from the subsurface Miocene-Pliocene of
Enewetak Atoll. Specimens from recent sediments of Fiji are more similar to the holotype specimen and are confidently placed in this species. Orionina flabellacosta Holden 1976, differs from
0. brouwersae in having a curved ventral ridge, lacking the short anterior ridges and having larger
Occurrence.-Miocene t o Pleistocene of Enewetak Atoll; Recent off Fiji.
cf. 0. ERUGA Bold, 1963
(Pl. 1, figs. 11, 12)
Remarks.-The specimens illustrated in Plate 1 from the Pliocene Cubagua Formation of
Venezuela have a stronger ridge than those illustrated by Bold (1 963) from the Miocene of Trinidad.
FLABELLACOSTA Holden, 1976
1976, p. F20, PI. 3, figs. 5-7; PI. 1 1 , fig. 6.
(1 976) described and illustrated this species from the Miocene of Midway,
VAUGHANI (Ulrich and Bassler, 1904)
(PI. 1, figs. 5, 6, 9, 10; PI. 2, figs. 1-10)
Cythere serrulata BRADY,1869, p. 153, PI. 18, figs. 1 1 , 12.
Cythere vuughani ULRICH
1904, p. 109, PI. 38, fig. 25.
Cythereis reticulata HARTMANN,
1956, p. 37, figs. 45-52.
1967, p. 86, PI. 3, figs. 5a, b; PI. 4, figs. 6a-c; Text-figs. 50d-g, 5 4 ~ .
Remarks.-As discussed in detail above, we believe Orionina vaughani, 0. serrulata, 0. pseudovaughani and 0. reticulata constitute different populations and morphotypes of the same species.
Although serrulata was described by Brady in 1869, Bold (1963) was not able to find its holotype
and Swain (1967) expressed concern over the confusing status of this species. We therefore use
vaughani to refer to this well known species.
We gratefully acknowledge the help of the following colleagues who freely loaned us specimens
of Orionina for study: Drs. M. L. Gamero, J. E. Hazel, M. Kontrovitz, F. M. Swain, W. A. van
den Bold, T. R. Waller. Thanks go to Lt. Col. Robert F. Couch, Jr., Ms. E. E. Compton-Gooding
and Dr. E. M. Brouwers for their help with the Marshall Islands material. Dr. Joseph E. Hazel
(Louisiana State University) and Dr. Norman F. Soh1 (U. S . Geological Survey) provided helpful
reviews of the manuscript and invaluable taxonomic advice.
938 T. M. CRONIN
1963. The ostracode genus Orionina and its species. J. Paleont., 37 (I), 33-50.
- 1965. Middle Tertiary Ostracoda from northwestern Puerto Rico. Micropaleontology, 11, (4) 381-414.
BRADY, G.s. 1869. Description of Ostracoda from Hongkong, Nouvelle Providence, Saint Vincent, Golfe de Gascogne, Colon Aspinwall, Porte au Prince. In DE FOLIN et PERIER: Fonds de la Mer, 1, 113-176, PIS. 14-19.
- 1880. Report on the Ostracoda dredged by H.M.S. Challenger during the years 1873-1876. Report of Scientific
Results of the Voyage of H.M.S. Challenger, Zoology, 1, pt. 3, 1-184, pls. 1-44.
CRONIN, T.M. (this volume). Geographical isolation in marine species: Evolution and speciation in Ostracoda, I.
DIAS-BRITO, D., MOURA, J.A. and WURDIG, N. (this volume) Relationships between ecological models based on OStracods and foraminifers from Sepetiba Bay (Rio de Janeiro-Brazil).
GUNTHER, F.J. and SWAIN, F.M. 1976. Evolutionary trends in Orionina under conditions of geographic isolation during
the Neogene. Abh. Verh. naturwiss. Ver. Hamburg, (NF) 18/19 (suppl.), 141-152.
HARTMANN, G . 1956. Wietere neue marinen Ostracoden aus Brasilien. In TITCHAK, E. and KOEPCKE, H.W. (eds.). Beitruge zur neotropischen Fauna, 1(1), 18-62.
HATHAWAY, J.C. 1971. Data file, Continental Margin Program, Atlantic Coast ofthe United States, VOl. 2, sample Collection andanalyticaldata. Woods Hole Oceanographic Institution Reference no. 71-1 5 (unpublished manuscript).
HAZEL, J.E. and CRONIN, T.M. (this volume) The North American ostracode genus Climacoidea Puri, 1956, and the
tribe Campylocytherini Puri, 1960 (Neogene and Quaternary).
HOLDEN, J.C. 1976. Late Cenozoic Ostracoda from Midway Island drill holes. U.S. Geol. Surv. Prof. paper 680-F,
F1-41, 14 PIS.
PLUSQUELLEC, P.L. and SANDBERG, P.A. 1969. Some genera of the ostracode subfamily Campylocytherinae. Micropaleontology, 15(4), 427-480.
POAG, C.W. 1972. New ostracode species from the Chickasawhay Formation (Oligocene) of Alabama and Mississippi.
Rev. Espan. Micropaleontol., 4(1), 65-96.
PURI, H.S. 1953. Contribution to the study of the Miocene of the Florida Panhandle. Part 111: Ostracoda. Florida
Geol. Surv. Bull., 36, 217-309, 17 pls.
SWAIN, F.M. 1967. Ostracoda from the Gulf of California. Ceol. Soc. Amer. M e m . , 101, 139 PP.
1969. Taxonomy and ecology of nearshore Ostracoda from the Pacific coast of North and Central America.
In NEALE, J.W. (ed.). The taxonomy, morphology and ecology of Recent Ostracoda, 423-474. Oliver and Boyd, Edinburgh.
-and GILBY, J.M. 1967. Recent Ostracoda from Corinto Bay, western Nicaragua and their relationships to some
other assemblages of the Pacific coast. J . Paleontol., 41(2), 306-344.
MILLER, P.L. and MANDELBAUM,E.C. 1964. Ostracoda from the Gulf of California. In VAN ANDEL, T. and SHOR,
G.G. Jr. (eds.). Marine Geology of the Gulf of California. Amer. Assoc. Petrol. GeoL Mem., 3, 395-397.
TEETER, J.W. 1973. Geographic distribution and dispersal of some shallow-water marine Ostracoda. Ohio J. sci.,
73 (I), 46-54.
-1975. Distribution of Holocene marine Ostracoda from Belize. In WANTLAND, K.E. and PUSEY, W.C. 111 (eds.).
Belize shelf-carbonate sediments, clastic sediments, and ecology. Amer. Assoc. Petrol. Geol., Studies in Geology.
ULRICH, E.O. and BASSLER, R.S. 1904. Ostracoda. I n Maryland Geological Survey, Miocene, 98-1 30, PIS. 35-38.
VALENTINE, J.W. and JABLONSKI, D. 1983. Speciation in the shallow sea: General patterns and biogeographic Controls. In SIMS, R.w., PRICE, J.H. and WHALLEY, P.E.S. (4s.). Evolution, timeandspace: The emergence of the biosphere. 201-226. Academic Press, London.
VALENTINE, P.C. 1976. Zoogeography of Holocene Ostracoda off western North America and PaleOClimatiC implications. US. Geol. Surv. Prof. Paper, 916, 47 pp. 14 pls.
BOLD, W.A. VAN DEN.