6 NEW UNIONIDiE, MELANID^E, ETC., 



dinal teeth rather small, tuberculate, double in both valves ; lateral teeth rather long, 

 lamellar, and nearly straight; anterior cicatrices distinct, large and well impressed; 

 posterior cicatrices confluent, rather large and slightly impressed ; dorsal cicatrices 

 small and placed over the centre of the cavity of the beaks ; cavity of the shell shallow 

 and wide ; cavity of the beaks very shallow and rounded ; nacre whitish, purple or 

 salmon colored and very iridescent. 



Remarks. — About a dozen of this species were sent to me by Dr. Emmons. Nearly 

 all of them are purple or salmon colored. It is closely allied to Tiehes, (nobis), but is 

 not quite so square, nor so truncate at the posterior margin. The cardinal teeth are 

 larger and not so oblique. The adults are without rays, while the younger are ob- 

 scurely rayed on the posterior half of the disk and have two dark rays from the tips 

 to the posterior margin on each valve. The epidermis of liehes is also darker. The 

 undulations of the tips are few and not fine. 



Unio Raleighensis. pi. 1, fig. 2. 



Testa Isevi, oblonga, inflata, valde inaequilaterali, postice obtuse biangulata, antice rotundataj valvulis 

 subcrassis, antice crassioribus ; natibus subprominentibus ; epidermide luteo-fusca vel rufo-fusca, valde 

 . radiata ; dentibus cardinalibus parviusculis, in utroque valvule duplicibus ; lateralibus longis, lamel- 

 latis subcurvisque ; margarita alba vel purpurea et iridescente. 



Shell smooth, oblong, inflated, very inequilateral, obtusely biangular behind, 

 rounded before ; valves somewhat thick, thicker before ; beaks somewhat prominent ; 

 epidermis yellowish brown or reddish brown and very much rayed ; cardinal teeth 

 rather small and double in both valves ; lateral teeth long, lamellar and somewhat 

 curved ; nacre white or purple and iridescent. 

 Proc. Acad. Nat. Sci. 1863, p. 191. 



Biib. — Neuse River, six miles east of Raleigh, North Carolina, E. Emmons, M. D. 



My cabinet and cabinet of Dr. Emmons. 

 Diam. 1, Length !• 6, Breadth 2-7 inches. 



Shell smooth, oblong, inflated, very inequilateral, obtusely biangular behind and 

 rounded before ; substance of the shell rather thick, thicker before ; beaks somewhat 

 prominent ; ligament rather thick, short and dark brown ; epidermis yellowish brown 

 and reddish brown, very much rayed, with distant marks of growth ; umbonial slope 

 raised and obtusely angular; posterior slope rather broad and somewhat carinate; 

 cardinal teeth small, crenulate and double in both valves ; lateral teeth long, lamellar 

 and slightly curved ; anterior cicatrices distinct, rather large and well impressed ; 

 posterior cicatrices confluent, large and slightly impressed ; dorsal cicatrices placed 

 immediately over the centre of the cavity of the beaks ; cavity of the shell somewhat 

 deep and wide ; cavity of the beaks shallow and rounded ; nacre white or purple and 

 iridescent. 



