44 BULLETIN 104, UNITED STATES NATIONAL MUSEUM 



This variety is widely distributed in the West Indian region and 

 also in the Indo-Pacific, usually occurring with the typical form of 

 the species, 



SPIROLOCULINA ARENATA Cushman 



Plate 9, Figures 5 a, b 



Spirolpculina arenata Cushman, Proc. U. S. Nat. Mus., vol. 59, 1921, p. 63, 

 pi. 14, fig. 17; Publ. 311, Carnegie Instit. Washington, 1922, p. 62; Publ. 

 344, 1926, p. 80. 



Test compressed; chambers in a single plane, each much greater in 

 diameter at the initial end, gradually narrowing to the aperture, both 

 ends projecting beyond the ends of the preceding chamber; apertural 

 end produced into a rounded neck, periphery broadly rounded; sutures 

 deep and distinct; wall of sand-grains rather coarse for the size of the 

 test; aperture rounded. 



Length, 0.75 mm.; breadth, 0.30 mm.; thickness, 0.12 mm. 



This species originally described from the north coast of Jamaica 

 at Montego Bay has since been recorded from the Tortugas region 

 and from Porto Rico. It is probably widely distributed in the West 

 Indian region, and is one of the common species although of small 

 size. 



SPIROLOCULINA LIMBATA d'Orbigny 



Plate 9, Figures 6, 7 



The flattened forms of Spiroloculina have been greatly confused 

 as have most of the early species named hj d'Orbigny. A study of 

 original material from the type localities of Dax, Bordeaux, Castel 

 Arquato, and elsewhere has given much data as to what the types of 

 these species really are. The type specimens of S. limhata are from 

 Castel Arquato, Italy, in the Pliocene. Abundant material from 

 that locality has shown that S. limhata is very well figured by 

 d'Orbigny in the "planches in^dites" as given later by Fornasini. 



The sides are much excavated, the periphery broadly rounded and 

 the sides keeled. Such specimens occur off the coasts of Europe in 

 the Atlantic and Mediterranean, and to such material the specific 

 name ^S. limhata d'Orbigny should be applied. No material of the 

 western Atlantic can be referred to the species. 



This form has usually been erroneously referred by many authors 

 to S. depressa d'Orbigny. 



SPIROLOCULINA DEPRESSA d'Orbigny 



Plate 9, Figures 8, 9 



This is another of the species that has been greatly confused. The 

 localities given by d'Orbigny are the Mediterranean and fossil at 

 Castel Arquato. The original figure shows a very much flattened 

 species with the sides parallel and the periphery slightly concave or 

 truncate with the chambers slightly thickened at the peripheral edges. 



