78 DESCRIPTION OF NEW 



Shell smooth, elliptical, much compressed, striated, very inequilateral, rounded before 

 and subbiangular behind, flattened anteriorly to the umbonial slope; substance of the shell 

 rather thin; beaks slightly prominent; ligament rather short and very thin; epidermis dark- 

 brown — almost black, without rays, shining, with distinct marks of growth; cardinal teeth 

 small, compressed, double in both valves; lateral teeth very long, thin, lamellar and rather 

 curved; anterior cicatrices confluent, posterior cicatrices confluent; dorsal cicatrices 

 placed nearly in the centre of the cavity of the beaks; cavity of the shell very shallow: 

 cavity of the beaks very shallow ; nacre bluish-white and iridescent. 



Remarks. — Dr. Griffith called my attention to a single specimen of this shell in his 

 cabinet. The locality is uncertain, except that it is from some one of the southern states 

 — he thinks Alabama. In general form it resembles a very short, compressed nasatus, 

 Say. Like it it is flattened posteriorly, but it differs in its epidermis, and in the form of 

 the cardinal teeth. The umbonial slope is slightly biangular. It has somewhat the 

 aspect of U. multistriatus, (Nobis,) but it is a thinner shell. The beaks being eroded, the 

 characters could not be ascertained — but they have the aspect of some of the species from 

 South America. 



I name this after Amos Binney, M. D., of Boston, a gentleman who has devoted much 

 time to the development of our terrestrial Mollusca. 



Unio fuliginosus. PI. VII. Fig. 19. 



Testa Isevi, transversa, subcompressa ; valvulis sabcrassis ; natibus prominulis ; epidermide tenebroso-fuscn : 

 dentibus cardinalibus patois; lateralibus longis curvisque; margaritd vel alba vel purpurea. 



Shell smooth, transverse, rather compressed; valves rather thick; beaks slightly prominent; epidermis dark- 

 brown; cardinal teeth small; lateral teeth long and curved; nacre white or purple. 



Hab. Cobb's Creek, near Philadelphia. R. E. Griffith, M. D. 



My cabinet and cabinet of Dr. Griffith. 

 Diam. .7, Length 1.1, Breadth 2.2 inches. 



Shell smooth, transverse, rather compressed, subangular behind, carinate on the pos- 

 terior dorsal margin; substance of the shell rather thick; beaks slightly prominent; liga- 

 ment rather long and thin; epidermis dark-brown, smooth, somewhat polished, without 

 rays, with distant distinct lines of growth; cardinal teeth small, pointed, single in the right 

 and double in the left valve; lateral teeth long, curved upward, and thickened at the pos- 

 terior end; anterior cicatrices distinct; posterior cicatrices distinct; dorsal cicatrices 

 placed nearly in the centre of the cavity of the beaks; cavity of the shell rather shallow 

 and rounded; cavity of the beaks shallow and somewhat angular; nacre white or purple. 



Remarks. — It must be considered as quite a remarkable circumstance that a new 

 species of Unio should have remained unobserved in the vicinity of Philadelphia, where 

 30 many zoologists have been, within the last thirty years, employed in researches. The 

 first individual captured by Dr. Griffith was obtained about six months since, in Cobb's 

 Cnck, near La Grange, the country seat of Manuel Eyre, Esq. Subsequently Dr. Grif- 

 fith found three more specimens, of different ages. All these are before me, and certainly 

 present characters distinct from any species known to that accurate and experienced 



