﻿148 UAMl'SILIS 



A very neat little shell, which seems to he sonicvvhat closely 

 allied to L. I'csicularis. It is smaller and lighter colored than 

 that species, and the posterior end of the female is somewhat 

 obli(]uely truncated, while in -vcsicidans it is evenly rounded, 

 lliere is a small shell in the National museum collection that 

 is probably this, which is considerably rayed. 



Subgenus Caruncuijna Simpson in Baker, 1898. 



Carmiculma Simpson in Bakeu, Moll. Chicago, Pt. I, 1892, 



p. 109; Syn., 1900, p. 563. — Ortmann, Ann. Car. Mus.. 



VIII, 1912, p. 337. 



Shell small, inflated, obovate, rather solid, covered with a 

 thick, dark, often cloth-like epidermis, which is rayless or only 

 feebly rayed ; beak sculpture consisting of rather strong, con- 

 centric ridges, which form, as a general thing, only a single, 

 rounded loop in front, and are strongly curved upward behind. 

 Pseudocardinals compressed, smooth on the inside, generally 

 reflexed upward, somewhat torn on the edges. Shell (|uite 

 commonly pointed posteriorly, that of the female truncated 

 obliquely on ])ost-base. Animal with marsupinm consisting of 

 a few large ovisacs (8 to 13) ; inner gill wholly or in part free 

 from the abdominal sac ; female often having a well-developed 

 caruncle on the mantle below the branchial opening. 



Type, Unio tcxascnsis Lea. 



C)rtmann, (1. c). considers this group a subgenus of Eury- 

 nia. 



Lampsii.is texasensis (Lea). 



Shell somewhat elliptical, subcompressed to inflated, beaks 

 low, but full in inflated specimens, sculptured with from seven 

 to nine sharp ridges, which fall in a single loop and are curved 

 upward rather suddenly behind to the posterior ridge, from 

 which they return towards the nucleus in nearly convergent 

 raised lines ; posterior ridge well marked ; surface covered with 

 a thick, brownish or blackish epidermis, which is often chest- 

 nut tinted in the umbonal region ; left valve with two com- 

 pressed, rag-ged pseudocardinals, which are slightly reflexed, 



