NEW FRESH WATER AND LAND SHELLS. 271 



Unio Sloatianus. Plate 16, Fig. 33. 



Testa plicatd, oblongd, subcompressd, valde incBquilaterali ; valvuUs crassis; natihus suhprominenti- 

 bus; epidermide subnigrd; dentibus cardinalibus subgrandibus ; lateralibus crassis longisque; margaritd 

 albd et purpurea. 



Shell plicate, oblong, rather compressed, very inequilateral; valves thick; beaks somewhat prominent; 

 epidermis nearly black; cardinal teeth rather large; lateral teeth thick and long; nacre white and purple. 



Hab. Chattahoochee River, Georgia. L. W. Sloat. 



My Cabinet, and Cabinets of Dr. Jay and Mr. Sloat of Mobile. 

 Diam. 1.5, Length 2.3, Breadth 4.2 inches. 



Shell folded, oblong, rather compressed, very inequilateral, biangular behind; 

 substance of the shell thick; beaks somewhat prominent; ligament long and 

 thick; epidermis nearly black; cardinal teeth rather large and striate; lateral 

 teeth tbick and long; anterior cicatrices distinct; posterior cicatrices confluent; 

 dorsal cicatrices placed under the plate between the cardinal and lateral teeth; 

 cavity of the shell shallow; cavity of the beaks shallow and angular; nacre 

 white with purple tints, iridescent behind. 



Remarks. — The specimen described was kindly lent to me by Dr. Jay, who 

 received it of Mr. Sloat, the latter gentleman having found but two specimens. 

 The specimen quoted as being in my Cabinet, was sent to me by Dr. Boykin 

 of Columbus, Georgia. I have classed it with the Sloatianus, with some hesi- 

 tation, as it diifers in being a thicker and more inflated shell, in being more 

 plicate, and in having an angle on the umbonial slope. The specimen is a 

 depauperated one, and when more perfect ones are observed, other characters 

 may be found, which would render it necessary to make a distinct species of it. 



Unto incrassatus. Plate 16, Fig. 34. 



Testa plicatd, triangulari, subinflatd; valvulis crassis; natibus subprominentibus ; epidermide sub- 

 nigrd; dentibus cardinalibus parvis ; lateralibus longis subreciisque ; margaritd salmonis colore tinctd, 

 vel purpured vel albd et iridescente. 



Shell plicate, triangular, rather inflated; valves thick; beaks somewhat prominent; epidermis nearly 

 black; cardinal teeth small; lateral teeth long and nearly straight; nacre salmon-coloured, purple or white 

 and iridescent. 



