﻿358 NEW UNIONID^ OF THE 



slightly impressed ; dorsal cicatrices placed on the under side of the cardinal tooth ; 

 cavity of the shell wide and shallow; cavity of the beaks rather deep and angular; 

 nacre silver white and somewhat iridescent. 



Soft parts. — Branchial uterus was not charged, but ova were in the ovarium. Branchial 

 large, very thin, semicircular, inner one very much the larger, free nearly two-thirds 

 the length of abdominal sack. Palpi large, thin, subtriangular, united half way 

 down the posterior edges. Mantle very thin, thickened on the edges. Branchial 

 opening rather large, with numerous small brownish papillae. Anal opening rather 

 small, with smooth edges, devoid of all appearance of papillae. Super-anal opening 

 very large, colored on the inner edges and united below. Anus very small'; color of 

 the mass dirty white. 



Remarks. — I received from Prof. Forshey two perfect specimens, one with the soft 

 parts and several old valves. The one figured is not full grown. It is a very 

 beautiful and interesting species, and very nearly allied to lacrymosus (nobis). It 

 differs in having small tubercles, and these are pretty regularly distributed over the 

 whole disk. It is also much more compressed, and the tubercles on the anterior and 

 posterior slopes are more numerous and more regularly placed in rows. In this respect 

 I have seen no Vnio so ornate. It also has a close resemblance to a half grown IT. 

 Blandianus (nobis), but is more compressed and has more and smaller tubercles. 

 The interior is remarkably white, and the surface of the nacre down the medial 

 portion is beautifully waved by the tubercles on the exterior. 



The specimen from Mr. Anthony is higher on the umbonial slope, where it is more 

 corrugate and the posterior slope also is higher. 



I dedicate this species to Prof. Forshey, who has done much to elucidate the 

 Natural History of the Southern States. 



Unio Houstonensis. PL 60, fig. 183. 



Testa laevi, subrotunda, subinflata, sequilaterali, ad latere paulisper planulata ; valvulis subcrassis, antice 

 crassioribus ; natibus elevatis, ad apices paulisper undulatis ; epidermide laevi, luteo-fusca, vel eradiata 

 vel obsolete" radiatii ; deatibus cardinalibus magnis, erectis, crenulatis ; lateral ibus curtis subrectisque; 

 margarita argentea et iridescente. 



Shell smooth, nearly round, somewhat inflated, equilateral, a little flattened on the 

 side ; valves rather thick, thicker before ; beaks raised, slightly undulate at the tips ; 

 epidermis smooth, yellowish brown without rays or obscurely rayed ; cardinal teeth 

 large, erect and crenulate ; lateral teeth short and straight ; nacre silvery white and 

 iridescent. 



Proc. Acad. Nat. Sci. 185D, p. 155. 



Hab. — Houston, F. Moore, M. D. ; and Rutersville, Texas, Prof. Forshey. 



My cabinet and cabinets of Dr. Moore and Prof. Forshey. 

 Diam. 1-1, Length 1*3, Breadth 1-3 inch. 



