VALVATA. 49 



Inhabits the river Delaware. Rare. Found by Mr. Le Sueur, whose 

 proposed name is here adopted. (Say.) 



Cyclostoma tricarinata, Say, J. Acad. N. S. Phil. 1, 13, 1817 ; Nich. Ency. 

 ed. 3 ; Binney's ed. p. 08, 59, 56. 



Valvata tricarinata, Say, Journ. Acad. II, 173 ; Binney's ed. 68. — De- 

 SHAYES in Lam. VIII, 507 ; Tr. El. de Conch, pi. Ixsii, f. 4-6. — Menke, 

 Zeit. f. Mai. 1845, p. 121.— Haldeman, Hon. Ill, pl. i, f. 1-4.— Gould, 

 Invert. 225, f. 156.— DeKay, N. Y. Moll. p. 118, pl. vi, f. 130. 



Valvata carinata, Sowerby, Gen. Shells, xli, f. 2. 



Valvata unicarinata, DeKay, N. Y. Moll. 118, pl. vi, f. 129. 



Valvata bicarinata, Lea? Tr. Am. Phil. Soc. IX, 21 ; Proc. II, 83; Arch, 

 f. Nat. 1843, II, 129. 



Tropidina carinata, Chenu, Man. de Conch. II, 312, fig. 2232. 



Troschel (G-ebiss der Schueckeu, p. 96, pl. vi, f. 14) figures 

 the lingual ribbon of this species. 



This is a very variable species, as shown by No. 8981 of the 

 collection. Variety simplex is contained in No. 8982 ; 

 bicarinated forms in 8941. Mr. Say's specimens of ^^' 

 Valvata tricarinata are still preserved in the collection 

 of the Philadelphia Academy of Natural Sciences. 

 From an examination of them and of Mr. Lea's origi- 

 nal Valvata bicarinata I am convinced of the identity 

 of the two. I have given (fig. 85) a figure of Mr. Lea's shell 

 and his description below. Haldeman refers it with doubt to 

 tricarinata. 



I have not seen authentic specimens of the other species men- 

 tioned in the synonymy. The original descriptions and fac-similes 

 of the original figures now follow. 



Valvata bicarinata. Lea — Shell orbicular, flattened above, bicarinata, 

 rather thick, horn-colored above, whitish below, widely umbilicate ; su- 

 tures impressed ; spire depressed ; whirls four, convex ; aperture rounded, 

 whitish within. 



Body rather short and white, head large, tapering, slightly enlarged at 

 the anterior termination, with a black mark passing 

 from the neck between the eyes, tapering off and 

 reaching nearly to the end of the snout, where there 

 are two oblique black marks bordered in front by 

 white, and accompanied behind by several irregular 

 white spots, the anterior ones being the larger. 

 Branchia translucent, superior portion blackish, bor- Valvata bicarinata. 

 dered with white spots and occasionally obtruded ; 



eyes round and deep black, placed at the posterior base of the tentacula, 

 surrounded by a white area ; tentacula long, rather tapering, obtuse at the 



