FORAMINIFERA OF NORTH PACIFIC OCEAN. 97 



CASSIDULINA CRASSA d'Orbigny. 



Cassidulina crassa d'Orbigny, Foram. Am6r. Merid., 1839, p. 56, pi. 7, figs. 

 18-20; For. Foss. Vienne, 1846, p. 213, pi. 21, figs. 42, 43.— Egger, Abh. 

 kon. bay. Akad. Wiss. Miinehen, CI. n, vol. 18, 1893, p. 303, pi. 7, figs. 35, 

 36.— Goes, Kongl. Svensk. Vet. Akad. Handl., vol. 25, No. 9, 1894, p. 43, pi. 

 8, figs. 421, 422.— Egger, Nat. Ver. Passau, Jahr. 16, 1895, p. 19, pi. 9, fig. 

 19.— Silvestri, Mem. Pont. Aecad. Nuovi Lincei, vol. 12, 1896, p. 104, pi. 2, 

 figs. 11, 12.— Flint, Rep. U. S. Nat. Mus., 1897 (1899), p. 292, pi. 38, fig. 3.— 

 Millett, Journ. Roy. Micr. Soc., 1901. p. 2. — Sidebottom, Mem. Proe. Man- 

 chester Lit. Philos. Soc., vol. 49, No. 5, 1905, p. 17.— Bagg, Proc. U. S. 

 Nat. Mus., vol. 34, 1908, p. 139. 



Cassidulina laevigata, var. crassa Parker and Jones, Philos. Trans. Roy. Soc, 

 vol. 155, 1865, p. 377, pi. 15, figs. 5-7; pi. 17, fig. 64d. 



Cassidulina obtusa "Williamson, Rec. Foram. Great Britain, 1858, p. 69, pi. 6, 

 figs. 143, 144. 



Description. — Outline subcircular or oval, biconvex, with a 

 broadly rounded peripheral border; chambers rather few, short, and 

 inflated, the surface depressed at the sutures; wall calcareous, perforate, 



a ^— ^ b ^m^r 



Fig. 151.— Cassidulina crassa. X 30. a, apertural view; 6, dorsal view; <•, ventral view. 



smooth; aperture a long narrow slit just below and nearly parallel 

 to the periphery of the test, with a long tooth partially filling the 

 aperture; color, white. 



Diameter, 0.60-1.00 mm. 



Distribution. — Brady records this species from five stations in the 

 North Pacific at depths varying from 40 to 2,475 fathoms. Bagg 

 records it from Albatross stations H4440 and H4694, in 1,259 and S65 

 fathoms, respectively, off the Hawaiian Islands. I have had material 

 from three stations off Japan, in 120-142 fathoms, from the Okhotsk 

 Sea in 100 fathoms, from the vicinity of the Aleutian Islands, in 500 

 fathoms, and from off California, in 65 fathoms. This gives a rather 

 general distribution for the area, and specimens are usually in con- 

 siderable numbers when found. The broadly rounded periphery will 

 distinguish this species from C. Isevigata, and its more narrow and elon- 

 gate aperture and more numerous chambers from C. subglobosa. When 

 71112°— Bull. 71, pt 2—11 7 



