﻿ANODONTA 433 



Margaron (Anodonta) globosa Lea, Syn.. 1852, p. 51 ; 1870, 



p. 81. 

 Anodon nopalatensis Sowrrby, Conch. Icon., XVII, 1867, pi. 



XVI, fig. 58.— Clkssin, Conch. Cab. Ano.. 1876, p. 223, pi. 



1.XXI11, fig. 3. 

 Margaron (Anodonta) nopalatensis Lea, Syn., 1870, p. 81. 



A magnificent species of the largest size. The posterior 

 point is higher than it is in tabascensis, the great swelling of 

 the beaks and umbonal region is much longer than it is in that 

 species. Lea's globosa is, I am sure, a young specimen of Sow- 

 erby's nopalatensis and his name has priority. 



Anodonta tabascensis Morelet. 



Shell large, slightly inequilateral, much inflated, irregularly 

 elliptical, thin, with very full, high beaks, whose sculpture con- 

 sists of a few nodulous, doubly-looped ridges ; anterior upper 

 part angulated; post-dorsal part developed into a small wing, 

 which meets the truncation of the posterior slope at an angle ; 

 posterior ridge low, ending in a narrow biangulation at the 

 median line; surface finely, concentrically striate; epidermis 

 smooth and shining, grayish-green, with two or three wide 

 rays on the posterior slope; interior bluish-white, iridescent. 



Length 150, height no mm. 



Length 156, height 116, diam. 80 mm. 



Tabasco, Mexico. 

 Anodonta tabascensis Morei.ET, Jl. de Couch., XXXII, 1884, 



p. 124.— Fischer and Crosse, Miss. Sci., il, 1894, p. 530, 



pi. LXII, fig. I. 



Anodonta tabascoensis Simpson, Syn., 1900, p. 646. 



Several fine shells were recently received by the National 

 Museum from Montecristo, Tabasco, Mexico, which I refer 

 to this species. They are a little higher in proportion to length 

 than the shell figured by Fischer and Crosse, and fuller in the 

 post-basal region, but the difference is not great. It is a mag- 

 nificent species and is nearest to A. globosa Lea, but the beaks 

 and umbonal swelling are not so much lengthened as they are 

 in that species, and the basal line is more rounded. 



