FORAMINIFERA OF THE ATLANTIC OCEAN. 15 



RHABDAMMINA ABYSSORIM W. B. Canionter. 



Plate 6, fig. 1: plate 7, fig. I. 



Rhabdammina abyssorum M. Sars. Fi3rh. Vid. Selsk. ChriBtiania, ISttS, p. 248 

 {nomen midum). — W. B. ('arpkntkk. Ann. Mag. Nat. Hist., ser. 4, vol. 4, 

 18G9, p. 288; Proc. Roy. Soc. London, vol. 18, 1869, p. 60.— G. O. Sars, 

 Forh. vid. Selsk. Chrietiania, 1871, pp. 250, 251. — Carpenter, The Micro- 

 scope, ed. 6, 1881, pp. 562, 563, figs. 321c, d (in text).— H. B. Brady, Rep. 

 Voy. Challenger, Zoolog>', vol. 9, 1884, p. 266, pi. 21, figs. 1-13.— De Folin, 

 Le Naturaliste, vol. 9, 1887, p. 127, fig. 12a. — A. Agassiz, Bull. Mus. Comp. 

 Zool., vol. 15, 1888, pp. 162, 163, figs. 492. 493 (in text).— Newmayr, Stamme 

 Thierreichs, vol. 1, 1889, p. 173, fig. 17a (in text).— Egger. Abh. Bay. 

 Akad. Wiss. Miinchen. vol. 18, 1893, p. 255, pi. 4, fig. 31.-Goes, Kongl. 

 Svensk. Vet. Akad. Handl., vol. 25, No. 9, 1894, p. 19, pi. 4, figs. 67, 68.— 

 Schltjmberger, M^m. Soc. Zool. France, vol. 7, 1894, p. 254. — Goes, Bull. 

 Mus. Comp. Zool., vol. 29, 1896, p. 21. — Kiaer, Norske Nordhavs. Exped., 

 No. 25. 1899, p. 4.— Flint, Rep. U. S. Nat. Mus.. 1897 (1899), p. 271, pi. 

 12, fig. 2.— Rhumbler, Arch. Prot., vol. 3, 1903, p. 264, fig. 108 (in text).— 

 CusHMAN, Bull. 71. IT. S. Nat. Mus., pt. 1. 1910, p. 24, figs. 8-10 (in text).— 

 Awerinzew, Mem. Acad. Imp. Sci. St. Petersburg, ser. 8, vol. 29. No. 3, 

 1911, p. 10.— Pearcey. Trans. Roy. .Soc. Edinburgh, vol. 49, 1914, p. 998.— 

 IIerox-Ali,en and Earland. Trans. Linn. Soc. London, vol. 11. pt. 13, 

 1916, p. 221. 



Rhabdammina abyssorum., var. robusta Goes, Kongl. Svensk. Vet. .\kad. Handl., 

 vol. 19, No. 4, 1882, p. 143, pi. 12, figs. 430, 431. 



Astiorhiza abyssorum Eimer and Fickert, Zeitschr. Wiss. Zool.. vol. 65, 1899, 

 p. 666. 



Description. — ^Test free, consisting of a central subglobular chamber 

 with typically three radiating arms, varymg in number to five, of 

 nearly uniform diameter, with no divisions; when three, usually in 

 the same plane but the accessory arms above this number often 

 added in a different plane; wall of sand gi*ains, firmly cemented, 

 with a reddish brown cement often giving a decided tinge of color 

 to the whole test, interior fairly smooth and reddisli from the color 

 of the cement, exterior roughly finished; apertures formed by the 

 circular openings at the ends of the tubular arms. 



Length of test with the arms, up to 20 mm. 



Disfrihution.— In colder waters this is a very widely distributed 

 species. It is recorded from the Arctic off Greenland, Norway, and 

 to the north of Siberia about Great Britahi, Bafhns Bay, Gulf of 

 Mexico, and the Caribbean Sea. On the western coast of the Atlantic 

 it has occurred frequently in tlie Alhatross material. In the long 

 list the stations range in depth from 82 to 2,045 fathoms and the 

 bottom temperatures from 36.8° to 41° F., with a single station in 

 the Gulf of Mexico 51.6° at 106 fathoms. 



The best development of the species is in the colder water from 

 C.ipe Hatteras northward to tl:e Xewfoundland Banks. 



Tlic foil owins: V arid V i^ distiiisriiishe*]: 



