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BULLETIN 104, UNITED STATES NATIONAL MUSEUM 



be accomplished by a careful study of original material on which these 

 records were based. 



Brady's figures have undoubtedly been followed by many later 

 authors. He has two species, one of which (pi. 8, fig. 1) is Discorbis 

 advena Cushman. The other is an Indo-Pacific species common 

 especially in the Australian region and unlike the western Atlantic 

 forms which have been assigned to "Discorbina rosacea." 



DISCORBIS SUBARAUCANA Cushman 



Plate 7, figures 2 a-c 



Discorbis subaraucana Cushman, Publ. 311, Carnegie Instit. Washington, 

 1922, p. 41, pi. 7, figs. 1, 2; Publ. 344, 1926, p. 78. 



Test unequally biconvex, dorsal side somewhat arched, the ventral 

 side very slightly convex, flattened, or even somewhat concave; 

 periphery not lobulated, composed of about 2.5 coils, six to eight 

 chambers in the last-formed one; sutures oblique, curved, limbate 

 on the dorsal side, except in the last two or three chambers in the 

 adult, ventrally also somewhat limbate, especially in the early stages; 

 wall with numerous punctae; aperture at the base of the ventral side of 

 the last-formed chamber, narrow; color of the earlier chambers red- 

 dish-brown, those of the last-formed ones usually white. 



Diameter up to 0.40 mm. 



This species is common in the West Indian region, and extends up 

 the coast of the United States in the warmer waters to south of 

 Cape Cod. It is also probably widely distributed in the Indo-Pacific. 



As a fossil it occurs in the Miocene, Choctawhatchee marl, of Florida. 



Discorbis subaraucana — Material examined 



