FORAMINIFERA OF THE BYEAM CALCAREOUS MARL AT BYRAM, MISS. 



95 



from the Philippine region, where this species 

 attains a large size. This is by far the largest 

 of the Byram species but is not so common as 

 some of the others. The truncate apertural 

 end is the usual character in both the fossil and 

 recent material of this form. 



Polymorphina amygdaloides (Reuss) Reuss. 



Plate XVIII, figures 2a, 2b. 



Olobiilina amygdaloides Reuss, Deutsch. geol. Gesell. 



Zeitschr., vol. 3, p. 82, pi. 6, fig. 47, 1851. 

 Polymorphina amygdaloides (Reuss) Reuss, Akad. Wiss. 



Wien Sitzungsber, vol. 18, p. 250, pi. 8, fig. 84, 1855. 

 H. B. Brady, Challenger Rept., Zoology, vol. 9, p. 560, 



pi. 71. fig. 13 (?), 1884. 

 Millett, Roy. Micr. Soc. Jour., p. 261, 1903. 

 Sidebottom, Manchester Lit. and Philos. Soc. Mem. 



and Proc, vol. 51, No. 9, p. 9, pi. 2, figs. 12-14, 



1907. 

 Bagg, U. S. Nat. Mus. Proc, vol. 34, p. 148, 190S. 

 Cushman, U. S. Nat. Mus. Bull. 71, pt. 3, p. 85, pi. 41, 



fig. 5, 1913. 



Test elongate-oval, much compressed, com- 

 posed of few chambers which are elongate and 

 narrow; sutures rather indistinct, not de- 

 pressed; surface smooth; aperture somewhat 

 produced. Length 0.65 millimeter or less. 



A few compressed, elongate specimens from 

 the Byram marl may best be referred to this 

 species. 



An examination of the figures of specimens 

 referred to this species by different authors will 

 show a very considerable range of forms. 



Genus TJVIGERINA D'Orbigny, 1826. 

 Uvigerina byramensis Cushman, n. sp. 



Plate XVIII, figure 5. 



Test minute, elongate, somewhat fusiform, 

 initial end pointed, chambers numerous, dis- 

 tinct, sutures depressed, surface ornamented by 

 longitudinal costae, rather thin and sharp, the 

 last-formed chamber more distinct than the 

 rest, the inner side concave, the other two sides 

 slightly convex, giving a generally triangular 

 section, the surface of this last-formed chamber 

 smooth, the apertural end produced into a 

 short cylindrical neck with a slight lip, the 

 aperture circular. Length 0.25 to 0.35 milli- 

 meter. 



This species, which is the only one of the 

 genus in the Byram marl at its type locality, is 

 very distinct and constant in its characters. 

 The size is very uniform, and the peculiar shape 

 of the last-formed chamber in the adult is 

 characteristic. 



FamUy GLOBIGERINIDAE. 



Genus GLOBIGERINA D'Orbigny, 1826. 



Globigerina builoides D'Orbigny. 



Plate XIX, figures 1-3. 



Globigerina builoides D'Orbigny, .\nnales sci. nat , vol. 7, 

 p. 277, No. 1, Modeles, Nos. 17, 76, 1826; in Barker, 

 Webb, and Berthelot, Histoire naturelle des lies 

 Canaries, pt. 2, Foraminif&res, p. 132, pi. 2, figs. 1-3 

 28, 1839. 

 H. B. Brady, Challenger Rept., Zoology, vol. 9, p. 593, 

 pi. 77; pi". 79, figs. 3-7, 1884. 



There are in the typical Byram marl but few 



specimens of either this species or G. triloha, 



listed below. The specimens referred to 6. 



iulloides are very constant in their characters 



and are of the form shown in the figures given. 



They are very similar except in their lower 



spire to the form figured by Brady in the 



Challenger report, plate 79, figure 7. There 



are but four visible chambers from the ventral 



side. 



Globigerina triloba Reuss. 



Globigerina triloba Reuss, .\kad. Wiss. Wien Penkschr., 

 vol. 1, p. 374, pi. 47, figs. lla-€, 1849. 



Globigerina builoides D'Orbigny var. triloba H. B. Brady, 

 Challenger Rept., Zoology, vol. 9, p. 595, pi. 81, 

 figs. 2, 3, 1884. 



Specimens which are very similar to the 

 species described by Reuss and figured by 

 Brady are found rarely in the Byram marl. 

 In all the specimens the three visible chambers 

 make up the whole of the exterior of the test. 

 The walls are very thin and translucent. 



FamUy BOTALnDAE. 

 Genus SPnULLINA Ehrenberg. 1841. 

 Spirillina subdecorata Cushman, n. sp. 



Plate XIX, figures 4, 5. 



Test discoidal, much flattened, consisting 

 of eight or more coils, slightly embracing, dor- 

 sal side slightly convex, ventral side strongly 

 concave in the middle, chamber broad, the 

 periphery with a broad, thin keel, the main 

 surface of the chamber on the dorsal side gran- 

 ular, ventral side more nearly smooth; aperture 

 at the end of the tube. Diameter about 0.5 

 millimeter. 



Several specimens of this same character 

 were found in the marl at Byram. One of these 

 is attached to a shell fragment by the ventral 

 side. 



This species is perhaps nearest in character 

 to S. decorata H. B. Brady, an Indo-Pacific 

 species. 



