﻿354 STROPHITL^S 



cjivitics sonicwliat deep, not compressed; muscle scars shallow • 

 nacre bluish or hluish-white. sometimes flesh-colored and 

 ])lotched in the cavities of the valves. 



Length 'jy, height 52, diam. 37 mm. 



Tombigbee River Mississippi. 



Type locality, 'rombigbec River, Columbus, Miss. 

 Margar'itana toiubrcbcctisis Lka, Pr. Ac. .\'. Sci., Phila., II. 



1858. p. 138. 

 Mnr-^aritmia tombi[:_brrtisis Lr.\, Jl. .\c. X. Sci. Phila., V. 1862. 



p. 107, pi. XVIII. fig. 2^c,: O'bs., VIII, 1862. p. iii. pi. xviii. 



fi?- 255. 

 Margaron ( Mary.ariiona ) iambi i^^bccnsis Li-.a. Svn., 1870. p. 



68. 

 Margaritana (Altt'Sinodonici) iornbigbeensis Ci.K-ssin, Conch. 



Cab. Ano., 1876. p. 268, pi. i,xxxi, figs. 3. 4. 

 Strohhitus tonibic'bccnsis Simpson, Syn., 1900. ]). 619. 

 Margaritana columbcnsis Lka, Pr. Ac. N. Sci. Phila., XI, 1867, 



p. 81. — Index, II, 1869, p. 23. — Simpson, Syn., 1900, p. 673. 



In this species the distinguishing characters are the peculiar 

 dark, rather dull epidennis with a few narrow, nearly yellow 

 rays, and sometimes with a few bright green ones, a most 

 peculiar pattern of coloring. The hinge line is rather more 

 curved than it is in either .S'. conna'Saugacnsis or S. spillmanii. 

 It resembles to some extent certain .specimens of S. cdciitiiliis, 

 but is a rather shorter species. 



Stropiiitus givSnerii (Lea). 



vShell somewhat elongated, subrhomboid. with the dorsal 

 and ventral lines nearly parallel, scarcely subsolid, somewhat 

 inflated ; beaks probably rather full and high, but much eroded 

 in the specimens examined, placed somewhat in front of the 

 middle ; posterior ridge moderate, very slightly double ; sur- 

 face covered with irregular, low .sulcations ; epidermis pale 

 greenish-brown, rayless or very faintly rayed ; left valve with 

 two or three low, vestigial pseudocardinals : right valve with 

 one low pseudocardinal ; laterals nearly or quite wanting; 



