40 BULLETIN 104, UNITED STATES NATIONAL MUSEUM 



Genus SPIROLOCULINA d'Orbigny, 1826 



Spiroloculina d'Orbigny (Genotype, by designation, Spiroloculina depressa 

 d'Orbigny), Ann. Sci. Nat., vol. 7, 1826, p. 298.— H. B. Brady, Rep. Voy. 

 Challenger, Zoology, vol., 9, 1884, p. 147. — Chapman, The Foraminifera, 

 1902, p. 89. — CusHMAN, Special Publ. No. 1, Cushman Lab. Foram. Res., 

 1928, p. 149. 



Miliola (part) Lamarck, Ann. Mus., vol. 5, 1805, p. 352 (and later authors) 



Test with the early chambers in the microspheric form quinque- 

 locuhne, the later ones in a single plane, chambers a half coil in length, 

 in the megalospheric form all the chambers usually in one plane; 

 apertural end usually with a neck and lip, simple, with a simple or 

 bifid tooth. 



Permian (?) Cretaceous to Recent. 



This is a more specialized genus than Massilina, and the character 

 of having chambers in a single plane is taken on very early even in 

 the microspheric form. There are a number of species referred to 

 Spiroloculina which belong elsewhere and it is probable that the 

 actual history of the restricted genus begins in the Cretaceous. 



SPIROLOCULINA GRATELOUPI d'Orbigny 



Plate 8, Figures 1 a-b 



Spiroloculina grateloupi t>' Orbigny , Ann. Sci. Nat., vol. 7, 1826, p. 298. — 

 Terquem, M^m. Soc. G^ol. France, ser. 3, vol. 1, 1878, p. 52, pi. 5, figs. 5, 

 6.— WiESNER, Arch. Prot., vol. 25, 1912, p. 208.— Cushman, Bull. 71, 

 U. S. Nat. Mus., pt. 6, 1917, p. 31, pi. 4, figs. 4, 5; Proc. U. S. Nat. Mus., 

 vol. 56, 1919, p. 634; Bull. 100, U. S. Nat. Mus., vol. 4, 1921, p. 396, pi. 

 78, figs. 4 a, b; pi. 100, fig. 3; text figs. 17, 18; Publ. 311, Carnegie Instit. 

 Washington, 1922, p. 59; Publ. 342, 1924, p. 56, pi. 20, figs. 3, 4; Publ. 

 344, 1926, p. 80. 



Spiroloculina excavata H. B. Brady (not d'Orbigny), Rep. Voy. Challenger, 

 Zoology, vol. 9, 1884, p. 151, pi. 9, figs. 5, 6. 



Test elongate, broadest in the center, tapering toward either end; 

 chambers rapidly thickening as added, in end view the periphery 

 much the broadest portion of the test, central portion deeply exca- 

 vated; periphery of the chambers in end view much convex, especially 

 in the central portion, the edges broadly rounded; chambers evenly 

 curved, the final chamber somewhat projecting, both at the base and 

 at the apertural ends, the latter having a decided neck with a phialine 

 lip, the aperture itself rounded and with either a single tooth with a 

 bifid end, the two projections forming a concave extremity, or in 

 some cases a pair of such bifid teeth opposite one another; surface 

 of the test dull, somewhat roughened. 



Length, 1.25 mm.; breadth, 0.60 mm.; thickness, 0.25 mm. 



This is typically a tropical species and best developed in the Indo- 

 Pacific. The species, however, occurs widely distributed in the West 

 Indian region, although specimens rarely exceed 1 millimeter in length 

 and are not so deeply excavated as those of the Indo-Pacific. 



