70 BULLETIN 161, UNITED STATES NATIONAL MUSEUM 



Subfamily Ophthalmidiinae 



Genus SPIROPTHALMIDIUM Cushman, 1927 



Spiroptlialmidium Cushman, Contr. Cushman Lab. Foram. Res., vol. 3, p. 37, 

 1927; Cushman Lab. Foram. Res. Spec. Publ. No. 1, p. 165, 1928; U. S. 

 Nat. Mus. Bull. 104, pt. 6, p. 90, 1929. 



Spiroloculina (part) H. B. Brady (not d'Orbigny), Rep. Voy. Challenger, Zool- 

 ogy, vol. 9, p. 154, 1884. 



Genoholotype. — Spiroloculina acutimargo H. B. Brady (part). 



Test similar to Ophthalmidium, but accelerated, the stage having 

 two chambers in a coil quickly reached; plate between the chambers 

 usually present; aperture simple, without teeth. 



There is a single species of this genus occurring in our material. 



SPIROPTHALMIDIUM ACUTIMARGO (II. B. Brady) 



Plate 16, Figures 5 a, b 



Spiroloculina acutimargo H. B. Brady (part), Rep. Voy. Challenger, Zoology, 

 vol. 9, p. 154," pi. 10, fig. 13 (not figs. 12, 14, 15), 1884— Balkwill and 

 J. Wright, Trans. Roy. Irish Acad., vol. 28, Sci., p. 323, 1885. — Siddall, 

 Proc. Lit. Phil. Soc. Liverpool, 1886, p. 72 (list).— Halkyard, Trans. Man- 

 chester Micr. Soc, 1889, p. 59. — Chaster, 1st Rep. Southport Soc. Nat. Sci., 

 1890-91, p. 55, 1892.— J. Wright, Proc. Roy. Irish Acad., ser. 3, vol. 1, p. 

 463, 1891.— Millett, Journ. Roy. Micr. Soc, 1898, p. 264.— Chapman, Journ. 

 Linn. Soc. Zool., vol. 28, p. 172, 1901. — Sidebottom, Mem. Proc. Manchester 

 Lit. Philos. Soc, vol. 48, no. 5, p. 6, 1904. — Earland, Journ. Quekett Micr. 

 Club, ser. 2, vol. 9, p. 192, 1905.— Bagg, Proc U. S. Nat. Mus., vol. 34, 

 p. 119, 1908.— Chapman, Journ. Linn. Soc. Zool., vol. 30, p. 396, 1910.— 

 Heron-Allen and Earland, Proc Roy. Irish Acad., vol. 31, pt. 64, p. 24, 

 pi. 1, fig. 8, 1913. — Chapman, Biol. Res. Endeavour, vol. 3, pt. 1, p. 6, 1915. — 

 Heron-Allen and Earland, Trans. Zool. Soc. London, vol. 20, pt. 17, p. 557, 

 1915; Trans. Linn. Soc. London, ser. 2, vol. 11, p. 20S, 1916.— Cushman, U. S. 

 Nat. Mus. Bull. 71, pt. 6, p. 31, pi. 5, fig. 1, 1917.— Sidebottom, Journ. Roy. 

 Micr. Soc, 1918, p. 5.— Cushman, U. S. Nat. Mus. Bull. 100, vol. 4, p. 398, 

 1921 ; Carnegie Inst. Washington Publ. 342, p. 56, 1924. 



Spiroptlialmidium acutimargo Cushman, Contr. Cushman Lab. Foram. Res., 

 vol. 3, p. 37, pi. 8, fig. 5, 1927; Cushman Lab. Foram. Res. Special Publ. 

 No. 1, pi. 20, fig. 7; pi. 21, fig. 5, 1928; U. S. Nat. Mus. Bull. 104, pt. 6, 

 p. 90, pi. 22, fig. 1, 1929. 



Test oval, much compressed, planispiral throughout, peripheral 

 margin carinate; development consisting of a proloculum followed 

 by several coils of an undivided second tubular chamber, then by 

 chambers a half coil in length separated by a wide flange; wall 

 smooth; aperture rounded, without a tooth. Length, 0.5 mm.; 

 breadth, 0.3 mm. ; thickness, 0.05 mm. 



The only specimens of this species are from three Albatross sta- 

 tions as given in Table 24. All the specimens are very typical. 



