74 BULLETIN 71, UNITED STATES NATIONAL MUSEUM. 



vol. 1, 1891, p. 468.— Chapman, Journ. Roy. Micr. Soc, 1892, p. 326, pi. 6, 

 fig. 11.— Egger, Abh. kon. bay. Akad. Wiss. Miinchen, vol. 18, 1893, p. 263, pi. 

 5, figs. 35, 36.— Goes, Kongl. Svensk. Vet. Akad. Handl., vol. 25, no. 9, 1894, 

 p. 31, pi. 6, figs. 238, 239.— Chapman, Proc. Zool. Soc. London, 1895, p. 17 — 

 Ann. Mag. Nat. Hist., ser. 6, vol. 16, 1895, p. 315, pi. 11, figs. 8, 9.— Goes, 

 Bull. Mus, Comp. Zool., vol. 29, 1896, p. 34.— Flint, Rep. U. S. Nat. Mus., 

 1897 (1899), p. 278, pi. 23, fig. 2.— Millett, Journ. Roy. Micr. Soc, 1899, p. 

 362.— Eimer and Fickert, Zeitschr. wiss. Zool., vol. 65, 1899, p. 614, fig. 32 

 (in text). — Rhumbler, Zeitschr. allg. Pbys., vol. 2, 1902, p. 1, fig. 18; 

 Arch. Protistk., vol. 3, 1903, p. 280, fig. 129 (in text).— Sidebottom, Mem. 

 and Proc. Manchester Lit. and Philos. Soc, vol. 49, No. 5, 1905, p. 5. 

 Ammodiscus tenuis H. B. Brady, Quart. Journ. Micr. Sci., vol. 21, 1881, p. 51; Rep. 

 Voy. Challenger, Zoology, vol. 9, 1884, p. 332, pi. 3S, figs. 4-6. —Goes, Kongl. 

 Svensk. Vet. Akad. Handl., vol. 25, No. 9, 1894, p. 31, pi. 6, figs. 240, 241. 

 —Chapman, Proc. Zool. Soc. London, 1895, p. 18.— Flint, Rep. U. S. Nat. 

 Mus., 1897 (1899), p. 279, pi. 23, fig. 1.— Rhumbler, Arch. Protistk., vol. 3, 

 1903, p. 281, fig. 130 (in text). 



Description. — Test composed of an ovoid proloculum and long 

 spirally coiled, undivided second chamber, coils in a single plane, 

 gradually increasing in size, in the microspheric form very small in 

 the center, in the megalospheric form much larger in the central 

 portion and increasing but little in succeeding coils, in the adult 

 condition chamber about as wide as high, building no floor of its 

 own, aperture at the open end of the chamber, wall arenaceous, 

 usually with an excess of cement, color usually a reddish or reddish- 

 brown, in alcoholic specimens and sometimes in dry ones with the 

 portion about the aperture white. 



Diameter of test up to 6 mm. 



Distribution. — Brady records a single station for this species in 

 the North Pacific. Besides this station the volume on the "Sum- 

 mary of Results" of "The Challenger Report" adds another, 237, 

 in 1,875 fathoms off Japan. Goes records the species as common 

 off the west coast of Mexico and Central America from six Albatross 

 stations. It is common in this material and from Station D3431, 

 from which there are 129 specimens selected by Goes. Flint records 

 it from Panama Bay in 51 fathoms. 



Besides these records I have found the species in material from 

 thirteen Albatross and Nero stations in- the North Pacific. These are 

 along the west coast of Mexico and the United States, at the entrance 

 to the Gulf of California, off San Diego and off Oregon ; two stations 

 near the Hawaiian Islands; from along the south coast of Honshu 

 Island, Japan, and near Guam. This gives a rather general distri- 

 bution, but one station being north of lat. 40° N. The depths range 

 from 20 to 3,125 fathoms, but only four stations are over 1,500 fathoms 

 in depth. Of the shallower stations, two are 20 and 51 fathoms, the 

 others between 250 and 1,150 fathoms, with the average of all less 

 than 1,000 fathoms for this area. 



