FOKAMINIFEKA OF THE BYKAM CALCAREOUS MARL AT BYEAM, MISS. 



91 



40 fathoms. It has also been found in the 

 lagoon of Funafuti and off the coast of Victoria 

 (Chapman); off Laysan (R humbler); and at 

 several localities off the Hawaiian Islands 

 (Bagg, Cushman). 



Most of the recorded specimens of the species 

 were obtained in 40 fathoms or less, although 

 off Fiji it was fomid at a depth of 255 fathoms, 

 and off the Hawaiian Islands at 249 to 305 

 fathoms. It is evidently most abundant on 

 tropical coral reefs of the south Pacific. 



Genus BOLIVINA DOrbigny, 1839. 

 Bolivina amygdalaeformis H. B. Brady. 



Plate XV, figure 3. 



Bolivina amyridalaefonui.t H. B. Brady, Quart. Jour. 

 Micr. Sci., vol. 21, p. 59, 1881; Chalhngcr Kept, 

 Zoology, vol. 9, p. 426, pi. 53, figs. 28, 29, 1884. 

 Cushman, V. S. Nat. Mus. Bull. 71, pt. 2. p. 42, figs. 

 69a, b (in text"), 1911. 



Test elongate, somewhat fusiform, thickest 

 in the middle, periphery well rounded, cham- 

 bers comparatively few; sutures hidden by 

 the ornamentation of the surface, consisting of 

 numerous longitudinal irregularly anastomos- 

 ing costae; the last-formed chambers lacking 

 the costae but with numerous large depres- 

 sions; aperture terminal, elongate-oval, some- 

 what constricted near the middle. Length 

 0.80 millimeter or less. 



This species is rare in the Byram marl, yet 

 it is very distinct. In its recent distribution it 

 is decidedly a Pacific form. It was originally 

 described by Brady from specimens obtained 

 off the Philippines at 95 fathoms, off the Ad- 

 mu-alty Islands at 16 to 25 fathoms, off the 

 north coast of New Guinea at 1,070 fathoms, 

 and in Torres Strait at 155 fathoms. I have 

 recorded specimens from two Albatross sta- 

 tions — D4875, in 59 fathoms, eastern channel 

 of Korea Strait, and D4964, in .37 fathoms, off 

 the southern coast of Japan. 



This is one of the species which shows the 

 relation of the Byram marl fauna to the exist- 

 ing fauna of the south Pacific, Australian, 

 East Indian, and Philippine regions. 



Bolivina nitida H. B. Brady. 



Plate XV, figure 4. 



Bolivina nitida H. B. Brady, Challenger Kept., Zoology, 

 vol. 9, p. 420, pi. 52, figs. 30a, b, 1884. 



Bolivina laevigata H. B. Brady (not B. laevigata D'Orbigny), 

 Quart. Jour. Micr. Sci., vol. 21. p. 57, 1881. 

 Test elongate, thin, complanate, broadest at the center. 



tapering and rounded toward the ends. Segments few 



in number, regvdarly toxtvilarian in arrangement; liroad, 

 flattened on both faces, and liordered both at sutures and 

 periphery by a narrow band of clear shell substance. 

 Sutures even; apertiu^e large, irregularly oval, oblique. 

 Length l/60th inch (0.42 millimeter). 



The above description, cjuoted from the 

 Challenger report, is very accurate for the 

 species as found in the Byram marl. The 

 specimen figured here is one of the most ex- 

 treme, the majority of the specimens being 

 very close to the figure given by Brady. The 

 large oblique aperture and the flattened test, 

 carinate, with the carinae continued between 

 and separating the chambers, are distinguish- 

 ing characters. 



Brady's material came from two Challenger 

 stations off Australia — off East Moncoeur 

 Island, Bass Strait, at .38 fathoms, and off 

 Raine Island, Torres Strait, at 155 fathoms. 

 The species was rare at both these stations, and 

 the lack of records elsewhere seems to show that 

 it is either local or rare. Its occurrence in the 

 Bjram marl is therefore decidedly interesting. 



Bolivina robusta H. B. Brady. 



Bolivina robusta H. B. Brady, Quart. Jotir. Micr. Sci., vol. 



21, p. 67, 1881; Challenger Rept., Zoology, vol. 9, p. 



421, pi. .53, figs, 7-9, 1884. 

 Egger, K. bayer Akad. Wiss. Miinchen Abh., CI. 2, 



vol. IS, p. 294. pl. 8, figs. 31, 32, 1893. 

 Millett, Roy, Micr. Soc. Jour., p. 543, 1900. 

 Cushman, V. S. Nat. Mus. Bull. 71. pt, 2, p. 36, figs. 59, 



60 (in text), 1911. 

 Heron-Allen and Earland, Zool. Soc. London Trans., 



vol. 20, p. 646, 1915. 



Test small, in front view rhomboid, thickest 

 along the median line, thence gradually sloping 

 to the sides; chambers numerous, usually much 

 lower than wide, slightly tumid, especially 

 in the last-formed portion, sutures distinct, 

 curved, slightly depressed, in the later cham- 

 bers often with the posterior side of the cham- 

 ber crenulate with numerous reentrants; wall 

 with numerous rather coarse perforations. 

 Length usually less than 0.5 millimeter. 



Small specimens of this species are common 

 in the B^Tam marl material examined. None 

 of the specimens have the stout apical spine 

 which appears in at least one form of the spe- 

 cies in its living form. 



There is probabl^^ more than one form or va- 

 riety of this species in recent seas. Most of the 

 specunens recorded by Brady were found in the 

 Pacific, especially the south Pacific. Later 

 records add numerous stations from the Pa- 

 cific, anil Heron-Allen and Earland record it 



