﻿STROPHTTUS 355 



beak cavities not deep; muscle scars sliallow ; nacre dull, tinted 

 purplish, slightly thicker in front. 



Length 92, height 55, diam. };] mm. 



Length 87, height 50, diam. t^^ mm. 



Type locality, Uphatipee Creek, Ala. Also Swamp Creek, 

 Alabama. 



Margaritana gesnerii Lea. Pr. Ac. N. Sci. Phila., U. 1858. p. 

 138; Jl. Ac. N. Sci. Phila., V. 1862, p. 211. pi. xxxii, fig. 



280; Ohs., IX, 1863, p. 33, pi. XXXII, fig. 280.— SOWERBY, 



Conch. Icon.. X\ I, 1868, pi. lxxxiv, fig. 446. 

 Margaron (Margaritana) gesnerii Lka. Svn., 1870, p. 67. 

 Margaritana gcssiierii Ri^tei, Conch. Sam.. III. 1890. p. 173. 

 Strohhitns gesnerii Simpson, Syn.. 1900. p. 619. 



This species resembles .S". eounasaiigaensis somewhat in ex- 

 ternal appearance, but it is more strongly sulcate and the teeth 

 are quite difl:'erent. In that species there is a strong, single 

 tooth ; in this there are two or three low vestigial ones in the 

 left valve and a single low one in the right. I am not positive 

 as to the generic position of this form, I have only seen two 

 rather badly eroded shells, the type and another specimen from 

 l^haupee Creek. It may not be a Stro/^hitus. but I do not 

 know where else to place it. 



Strophitus subvexus (Conrad). 



"Shell suboval, inflated ; thin ; anterior end rounded ; poste- 

 rior end subtruncated : posterior dorsal margin elevated and 

 abruptly rounded at the extremity ; callus resembling an in- 

 cipient tooth. 



Shell siTboval, inflated, thin, with prominent beaks, un- 

 dulated at the apex and not distant from the middle of the 

 valve : umbo inflated : umbonal region angtilated, and the 

 space behind with radiating lines ; epidermis olive and rather 

 obscurely rayed ; cavity very capacious, most so behind the 

 middle ; nacre bluish, stained with a light waxen-vellow. 



Length about 2 inches." (Conrad). 



Type locality. Black Warrior River, Ala. 



