96 BULLETIN 104, UNITED STATES NATIONAL MUSEUM. 



35, 36.— Goes, Kongi. 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 (part).— 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 te.'ct).— Rhumbler, Zeitschr. Allg. Phys., vol. 2, 1902, p. 1, fig. 18; 

 Arch. Proc, 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. — Cushman, 

 Bull. 71, U. S. Nat. Mus., pt. 1, 1910, p. 73, figs. 85, 86 (in text).— Heron- 

 Allen and Earland, Proc. Roy. Irish Acad., vol. 31, pt. 64, 1913, p. 49. — 

 Pearcey, Trans. Roy. Soc. Edinburgh, vol. 49, 1914, p. 1005. — Heron- 

 Allen and Earland, Trans. Linn. Soc. London, vol. 11, pt. 13, 1916, p. 225. 

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

 Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 332, pi. 38, 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. Prot., 

 vol. 3, 1903, p. 281, fig. 130 (in text).— ^Heron-Allen and Earland, Trans 

 Zool. Soc, vol. 20, 1915, p. 618. 



Descri2)tion. — Test free, planospiral, composed of an ovoid prolo- 

 culum followed by a long, spirally coiled, undivided second chamber 

 in a single plane, in the microsplieric form coils very small in the 

 center and gradually increasing toward the periphery, in the megalo- 

 spheric form coils much larger in the central portion and increasing 

 but little toward the peripheral region; adult with the outer whorls 

 about as wide as high in transverse section; wall finely arenaceous, 

 usually with an excess of cement; color usually yellowish or reddish 

 brown in fresh specimens or in alcoholic ones often with the area 

 about the a-perture whitish ; aperture formed by the open end of the 

 chamber. 



Diameter of test, up to 6 mm. 



Distribution. — This is a very widely distributed species. It has 

 been found in all the great oceans except the Arctic, Pearcey record- 

 ing it in his paper from the Antarctic. It is recorded from the 

 Mediterranean. In the Atlantic it is now known from the coasts of 

 France, Belgiimi, and the British Isles; from the North Sea; shores 

 of Noi-way and Sweden. This side of the Atlantic it has occurred 

 in material from Newfoundland southward, in the Gulf of Mexico 

 and Caribbean Sea as well as off the eastern coast of South America 

 near Baliia, Brazil. 



Most of the Atlantic records are from water less than a thousand 

 fathoms, the deepest 1,350 fathoms. Most of the Albatross material 

 "dredged off our coast is from between 500 and 1,000 fathoms in depth. 

 Most of the bottom temperatures range between 38.6° and 40.6° F. 



Both the microsplieric and mogalospheric forms are usually found 

 at the same station. The latter is the A. tenuis of Brady. Usually 

 in the Atlantic material, as elsewhere, the megalospheric form is 



