FORAMINIFERA OF THE ATLANTIC OCEAN 43 



the chambers with irregular raised costae, more or less obhque in 

 position; aperture at the end of the cyhndrical neck, rounded, with 

 a simple tooth; surface smooth, shining, but the wall very thin and 

 brittle. 



Length, 0.85 mm.; breadth, 0.60 mm.; thickness, 0.10 mm. 



This peculiar keeled species is known only from the Tortugas 

 region, but is to be looked for elsewhere in the West Indies. 



SPIROLOCULINA ANTILLARUM d'Orbigny 



Plate 9, Figure 3 



Spiroloculina aniUlarum u'Orbigny, in De la Sagra, Hist. Fis. Pol. Nat. 

 Cuba, 1839, " Foraminiferes,' p. 166, pi. 9, figs, 3, 4. — -H. B. Brady, Rep. 

 Voy. Challenger, Zoology, vol. 9, 1884, p. 155, pi. 10, figs. 21 o, h. — Cushman, 

 Bull. 100, U. S. Nat. Mus., vol. 4, 1921, p. 407, pi. 81, figs. 4 a, b; pi. 83, 

 fig. 4?; Proc. U. S. Nat. Mus., vol. 59, 1921, p. 63, pi. 14, figs. 14, 15; 

 Publ. 311, Carnegie Instit. Washington, 1922, p. 61; Publ. 342, 1924, p. 

 55, pi. 20, fig. 1. 



Test elongate, elliptical; chambers nearly circular in cross-section; 

 surface ornamented by numerous longitudinal costae, often slightly 

 oblique, both ends of the chamber projecting and the intermediate 

 portions thus left either filled by a plate of clear material or occasion- 

 ally open; apertural end projecting and forming a cylindrical neck 

 with a slight lip and a single tooth, sometimes bifid at the tip. 



Length, 0.95 mm.; breadth, 0.45 mm.; thickness, 0.15 mm. 



This species was originally described by d'Orbigny from shore sands 

 of Cuba. It is widely distributed and common in the whole West 

 Indian region and also in the Indo-Pacific. Brady took the name of 

 Spiroloculina grata Terquem for this species and it has been undoubt- 

 edly recorded many times under this name, but rarely figured. As 

 the species is one of shallow water coral-reef conditions probably it 

 is safe to accept most of the records of S. grata from such habitats 

 as really S. antillarum d'Orbigny. 



The following variety very often is found with the typical foim of 

 the species. 



SPIROLOCULINA ANTILLARUM d'Orbigny, var. ANGULATA Cushman 



Plate 9, Figures 4 a, b 



Spiroloculina grata H. B. Brady (part) (not Terquem), Rep. Voy. Challenger, 



Zoology, vol. 9, 1884, pi. 10, figs. 22, 23. 

 Spiroloculina grata Terquem, var. angulata Cushman, Bull. 71, U. S. Nat. 



Mus., pt. 6, 1917, p. 36, pi. 7, fig. 5. 

 Spiroloculina antillaram d'Orbigny, var. angulata Cushman, Bull. 100, U. S. 



Nat Mus., vol. 4, 1921, p. 408, pi. 81, figs. 5 a, b; Publ. 311, Carnegie 



Instit. Washington, 1922, p. 62; Publ. 342, 1924, p. 55, pi. 20, fig. 2; Publ. 



344, 1926, p. 80. 

 Variety differing from the typical in the angular form of the cham- 

 ber instead of cylindrical. 



