﻿66 NEW UNIONID^l OF THE 



very thick, very short, blunt at the ends, roughly striate and double in both valves ; 

 anterior cicatrices very distinct and very deeply impressed ; posterior cicatrices con- 

 fluent ; dorsal cicatrices numerous along the lower side of the cardinal tooth in a 

 row leading into the cavity of the beak; cavity of the shell rather deep ; cavity of 

 the beaks deep and subangular, nacre silver white, very pure and iridescent. 



Soft Parts. — Branchial uterus was not charged, but the ovarium of each of three 

 females examined, was filled with ova. Branchiae rather small, semicircular, inner 

 ones much the larger, the whole four leaves remarkably thick and were without any 

 ova, free nearly the whole length of the abdominal sack. Palpi large, oblique, suboval, 

 united more than half way down the posterior edges. Mantle rather thin, very much 

 enlarged anteriorly, and superiorly thickened at the edges, with a wide palleal border. 

 Branchial opening large, with numerous brownish papillae in groups and diverging. 

 Anal opening rather small and without any Papilla} or crenulations on the edges. 

 Super-anal opening very long and deep, slightly colored on the inner edges and united 

 below for a short distance. Color of the mass whitish. 



Remarhs. — I owe to the kindness of Bishop Elliott a fine suite of nearly all ages of 

 this beautiful species, among the finest of all the tuberculate group. It is nearly 

 allied to Rumphianus (nobis) and metanever Raf., and is the largest of the species which 

 belong to the group which embraces those species. It differs from them in having 

 a smooth umbonial slope, quite raised and rounded, while metanever has a number 

 of regular large tubercles and Rumphianus a larger number of small irregular tuber- 

 cles on this slope. Some individuals have tubercles over the whole disk except on 

 the umbonial slope, while others have only a few on the upper portions of it. Towards 

 the beaks and on them the tubercles are smaller, thickly set and disposed to arrange 

 themselves in rows forming an acute angle. The tubercles are usually pointed below 

 and lie like tears on the side as they do in lacrymosus (nobis). The teeth are enor- 

 mously large and massive and very much corrugated. The lateral tooth very short 

 and thick is in a direct line from the tip of the beak to the posterior margin. All the 

 cicatrices are deeply impressed including the palleal. I have great pleasure in naming 

 this beautiful species after my friend, Mr. Thomas Bland, who has done so. much for 

 American conchology. 



Unio concestator. PI. 12, fig. 48. 



Testa lsevi, elliptica, inflata, iDaequilaterali, antice rotundata ; valvulis subcraseis, antice crassioribus ; natibus 

 prominulis ; epidermide nigricente, eradiata, transverse striata ; dentibus cardinalibus subcrassis, in 

 utroque valvulo duplicibus crenulatisque ; lateralibus longis subcurvisque ; margarita vel purpurea 

 vel salinonis colore tincta et iridescente. 



Shell smooth, elliptical, inflated, inequilateral, rounded before ; valves rather thick, 

 thicker before ; beaks somewhat prominent ; epidermis nearly black, without rays, 



