FORAMINIFERA OF THE ATLANTIC OCEAN 89 



or more coils, the following chambers decreasing in relative length, 

 loose coiled, the intermediate area filled with a thin, shelly plate; 

 aperture at the open end of the chamber, rounded, without Up or tooth! 



Jurassic to Recent. 



This is a genus which has persisted since the Jurassic and is to be 

 considered primitive in many ways. The early stages connect it with 

 Cornuspira, the later chambers adding a new development that is 

 modified in the succeeding genera. 



OPHTHALMIDIUM INCONSTANS (H. B. Brady) 



Plate 21, Figures 8-11 



Hauerina inconstans H. B. Brady, Quart. Journ. Micr. Sci., vol 19 1879 

 p. 268. 



Ophthalmidiu7)i inconstans H. B. Brady, Rep. \oy. Challenger, Zoology, vol. 

 9, 1884, p. 189, pi. 12, figs. 5, 7, 8.— Siddall, Proc. Lit. Phil. Soc. Liver- 

 pool, 1886, p. 63 (list).— H. B. Brady, Parker, and Jones, Trans. Zool. 

 Soc, vol. 12, 1888, p. 216, pi. 40, figs. 12, 13.— Chaster, First Kept. 

 Southport Soc. Nat. Sci., 1890-91 (1892), p. 56.— J. Wright, Proc. Roy. 

 Irish Acad., ser. 3, vol. 1, 1891, p. 465.— Egger, Abhandl. kon. bay. 

 Akad. Wiss. Munchen, Cl. II, vol. 18, 1893, p. 244, pi. 3, figs. 6, 49.— 

 Chapman, Proc. Zool. Soc. London, 1895, p. 11. — Flint, Ann. Rept. U. 

 S. Nat. Mus., 1897 (1899), p. 302, pi. 47, fig. 3.— Millett, Journ. Roy. 

 Micr. Soc, 1898, p. 608. — Chapman, Journ. Linn. Soc Zool., vol. 30, 

 1910, p. 398; Biol. Res. Endeavour, vol. 3, pt. 1, 1915, p. 11.— Cushman, 

 Bull. 71, U. S. Nat. Mus., pt. 6, 1917, pp. 8, 28, pi. 3, figs. 1-4, fig. 6 in 

 text. — Sidebottom, Journ. Roy. Micr. Soc, 1918, p. 10, pi. 2, figs. 5-8. — 

 Cushman, Bull. 100, U. S. Nat. Mus., vol. 4, 1921, p. 393, pi. 78, figs. 2, 

 3. — Hanzawa, Jap. Journ. Geol. Pal., vol. 4, 1925 (1926), p. 37 (table). 



Ophthalmidium tumidulum H. B. Brady, Rep. Voy. Challenger, Zoology, vol. 

 9, 1884, p. 189, pi. 12, fig. 6.— Woodward, The Observer, vol. 4, 1893, 

 p. 77.— Millett, Journ. Roy. Micr. Soc, 1898, p. 608, pi. 13, fig. 2.— 

 KiAER, Rept. Norwegian Fish. Mar. Invest., vol. 1, No. 7, 1900, p. 29. — 

 Chapman, Journ. Linn. Soc. Zool., vol. 28, 1902, p. 399 (list). — Cushman, 

 Bull. 71, U. S. Nat. Mus., pt. 6, 1917, p. 28, pi. 3, fig. 5. 



Test planispiral, much compressed, chambers consisting of a glob- 

 ular proloculum, followed by a Cornuspira-\ike coiled second chamber, 

 making two or more coils, this in turn followed by chambers 

 progressively relatively shorter in length until the adult condition is 

 reached, where chambers are half a coil in length or less; chambers 

 nearly circular in transverse section with a thin wide flange on the 

 peripheral border, chambers often sHghtly less coiled toward the 

 apertural end, leaving a space filled by a thin plate of calcareous 

 material; aperture circular without lip or teeth. 



Diameter up to 1.5 millimeters. 



This is a widely distributed species from the records, usually in 

 fairly deep water. In the Atlantic there are records from about the 

 British Isles, off the coasts of the United States, off the Abrohlos 

 Bank, and in deeper water. 

 31569—29 7 



