280 DESCRIPTION OF NEW 



Hab. Alabama, Mr. C. M. Wheatley. 

 Cabinet of Mr. Wheatley. 

 Diam. .5, Length .8, Breadth 1.3 inches. 



Shell smooth, elliptical, rather inflated, inequilateral, angular behind ; substance of the 

 shell a little thick; beaks somewhat prominent, rounded, ligament short and thin; epider- 

 mis chestnut-coloured, shining, obsoletely rayed, with rather distant marks of growth ; 

 posterior slope rather depressed; umbonial slope slightly raised and round, cardinal teeth 

 rather small, compressed, very oblique, crenulate and double in both valves; lateral teeth 

 rather long, lamellar, curved and separated from the cardinal teeth ; anterior cicatrices 

 distinct; posterior cicatrices confluent; dorsal cicatrices placed on the under side of the 

 plate; cavity of the shell rather deep and regularly oval; cavity of the beaks small and 

 subangular; nacre salmon coloured. 



Remarks. — 'This is a small, regular and pretty-looking shell, of which only one specimen 

 was in Mr. Wheatley's collection. I could not place it in any species known to me. It 

 may not be a fully grown specimen. It is nearest in outline to U. co7istrictus, Con., in 

 those specimens where the margin is not constricted, which is often the case. It differs 

 from it in being a thicker shell, more regularly oval, and being fuller on the umbones and 

 on the umbonial slope. In the rays it also differs, having fewer, and these being more 

 distant. It is also rounder on the posterior margin. The nacre of the specimen before 

 me is of a pale salmon colour, inclining to rose. Other specimens will be likely to vary 

 in colour. 



Unio Troschelianus. PI. XXIII. Fig. 39. 



Testa Isevi, subobliqva, convexiusculd, inasquilaterali, poslice subangulata; valvulis crassis; natibus svb- 

 grandibus ; epidermide bruneo-oliva, striata, cradiatd ; dentibus cardinalities parvis, granulatis ; lateralibus 

 brevis, crassis reclisque; margaritd alba et iridescente. 



Shell smooth, suboblique, somewhat convex, inequilateral, subangular behind; valves thick; beaks rather large; 

 epidermis brownish-olive, striate, without rays; cardinal teeth small, granulate ; lateral teeth short, thick and 

 straight; nacre white and iridescent. 



Hab. Coosawattcc river, Murray county, Georgia, Dr. Boykin. 

 My cabinet. 

 Diam. .7, Length 1.1, Breadth 1.5 inches. 



Shell smooth, rather oblique, somewhat convex, inequilateral, subangular behind, 

 rounded before; substance of the shell thick, thinner behind; beaks rather large, sub- 

 medial; ligament rather short and thin; epidermis brownish-olive, striate, without rays, 

 and with very close marks of growth; posterior slope somewhat compressed; umbonial 

 slope rounded; cardinal teeth small, granulate, single in the right and double in the left 

 valve; lateral teeth short, thick and straight; anterior cicatrices distinct, posterior cica- 

 trices distinct; dorsal cicatrices placed on the under side of the plate; palleal cicatrix well 

 impressed; cavity of the shell rather shallow and rounded; cavity of the beaks very shal- 

 low and obtusely angular; nacre white and iridescent. 



Remarks. — Several specimens are before me, neither of which have perfect beaks. 



