﻿58 NEW UNIONIDiE OF THE 



thin, subangular, free nearly the whole length of the posterior edge. Mantle thin, 

 thickened at the margin, not colored except at syphonal openings. Branchial open- 

 ing rather large, with numerous rather small brown papillae on the inner edges. Anal 

 opening long, with numerous small brown papillae on the inner edges. Super-anal 

 opening long, slightly colored inside and united below for some distance. Color of the 

 mass whitish. 



Remarks. — This is a very common shell near Columbus. It belongs properly to the 

 group of which complanatus may be considered as the type; but it is wider and 

 more oblique, and the epidermis is darker and smoother. In the nacre it is very much 

 the same. Generally the interior, from the palleal cicatrix, is tinted with salmon, 

 while outside of the line of this cicatrix it is purple. I have seen none which were 

 entirely white, but a few were entirely purple. The undulations of the beaks are 

 small, rather rugose, making an inflection in the middle. The very young are usually 

 greenish, with distinct rays over the whole disk. In the next growth they are dark 

 brown, afterwards the epidermis becomes black or nearly so, and the rays entirely 

 disappear. When full grown the cardinal teeth usually are curved towards the pos- 

 terior margin. The epidermis on the side is usually smooth and shining. In outline 

 it approaches Unio Barrattii, (nobis,) but is more inequilateral and darker. 



Unio favosus. PI. 8, fig. 40. 



Testa lsevi, subtriangulari, subcompressa, ioequilaterali, postice subangulata ; valvulis subcrassis ; natibus 

 pioniinulis, ad apices undulatis; epidermide luteo-olivacea, virido-maculata ; dentibus cardinalibus 

 magnis erectisque; lateralibus crassis, sublongis subrectisque ; margarita argentea et valde iridescente. 



Shell smooth, subtriangular, rather compressed, inequilateral, angular behind; 

 valves thick ; beaks prominent, undulate at the tip ; epidermis olive yellow and 

 green spotted ; cardinal teeth large and erect; lateral teeth thick, rather long and 

 erect; nacre silvery and very iridescent. 



Proc. Acad. Nat. Sci., 1856, p. 262. 



Hob. — Othcalooga Creek, Gordon County, Georgia. Bishop Elliott. 



My cabinet and cabinet of Bishop Elliott. 

 Diam. - 8, To, Breadth 2 inches. 



Shell smooth, subtriangular, rather compressed, inequilateral, angular behind and 

 rounded before; substance of the shell thick, much thicker before; beaks prominent, with 

 two or three rather rough undulations at the tip ; lines of growth very distant, usually 

 five ; ligament short and rather thick ; epidermis dark olive yellow, with a row of 

 green broad spots before the umbonial slope, smooth at the umbo, but much striate 

 towards the margin ; umbonial slope slightly rounded ; cardinal teeth large, erect, 

 pyramidal, crenulate, single in the right and double in the left valve ; lateral teeth 

 thick, rather long, erect and nearly straight ; anterior cicatrices usually confluent, 

 and rather deep ; posterior cicatrices confluent ; dorsal cicatrices placed on the plate 



