66 BULLETIN 71, UNITED STATES NATIONAL MUSEUM. 



ture exserted, broad and rounded in side view, radiate; umbonal 

 portion of test often of clear shell material. 



Length up to 3 mm. 



Distribution. — Bagg records this species from a single Albatross sta- 

 tion H4696 in 376 fathoms off the Hawaiian Islands. I have had 

 material from four stations, all off Japan; H4882 in 248 fathoms, 

 bottom temperature 48.8° F.; D4893 in 106 fathoms, bottom tem- 

 perature 55.9° F.; D4895 in 95 fathoms; and D4964 in 37 fathoms, 

 bottom temperature 66.6° F. 



CRISTELLARIA ROTULATA (Lamarck). 

 Plate 35, fig. 3. 



"Cornu Hammonis seu Nautili" Plancus, Conch. Min., 1739, p. 13, pi. 1, fig. III. 



Lenticulites rotulata Lamarck, Ann. Mus., vol. 5, 1804, p. 188, No. 3; vol. 8, 1806, 

 pi. 62, fig. 11. 



Cristellaria rotulata d'Orbigny, M6m. Soc. Geol. France, ser. 1, vol. 4, 1840, p. 

 26, pi. 2, figs. 16-18.— Parker and Jones, Philos. Trans., vol. 155, 1865, 

 p. 345, pi. 13, fig. 19. — H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 9, 

 1884, p. 547, pi. 69, figs. 13a, b. — H. B. Brady, Parker, and Jones, Trans. 

 Zool. Soc, vol. 12, 1888, p. 224, pi. 64, fig. 15.— Egger, Abh. kon. bay. 

 Akad. Wiss. Miinchen, CI. n, vol. 18, 1893, p. 351, pi. 12, figs. 1, 2, 32, 33.— 

 Fornasini, Mem. Accad. Sci. 1st. Bologna, ser. 5, vol. 3, 1893, p. 435, pi. 2, 

 fig. 11; vol. 4, 1894, p. 221, pi. 3, figs. 24, 25.— Goes, Kongl. Svensk. Vet. 

 Akad. Handl., vol. 25, 1894, p. 60, pi. 10, figs. 559-578; Bull. Mus. Comp. 

 Zool., vol. 29, 1896, p. 54.— Flint, Rep. U. S. Nat. Mus., 1897 (1899), p. 317, 

 pi. 64, fig. 4.— Bagg, Proc. U. S. Nat. Mus., vol. 34, 1908, p. 148; Bull. 513, 

 U. S. Geol. Surv., 1912, p. 67, pi. 19, figs. 5a, b. 



Description. — Test large, close coiled, chambers numerous, lenticu- 

 lar, biconvex; wall smooth, thick; peripheral margin rather acute, 

 but not distinctly carinate; apertures of all chambers of visible test 

 usuaUy apparent. 



Length 1.5 to 4 mm. 



Distribution. — Brady records this species from a single North 

 Pacific Challenger station 232 in 345 fathoms south of Japan. Goes 

 records it from seven Albatross stations in the eastern Pacific at 

 depths varying from 660 to 1,201 fathoms. Bagg records it from 

 two stations near the Hawaiian Islands, Albatross D4000 in 104 to 213 

 fathoms and H4430 in 1,544 fathoms. I have had material from 

 Albatross station D3346 in 19 fathoms off Alaska and from several 

 stations near Japan, depths ranging from 437 to 712 fathoms and the 

 bottom temperatures from 37.5° to 39.8° F.; also from several Nero 

 stations in the same area. 



This species seems to differ from C. cultrata (Montfort) in the lack of 

 a definite keeled periphery, but many intermediate forms are found, 

 and such specimens are with difficulty placed in either one of the two 

 extreme forms. 



