SOLEMYA. 361 



and covered with a tliick black horny epidermis,, passing 

 over the edge of each valve. The hinge is without teeth, 

 and the interior presents a strong impression of the mantle. 

 This ligament^ as in all Solenacecij is external, but in this 

 genus its position is reversed, being placed on the short 

 side of the shell, above the umboes, which are generally 

 much eroded. 



A shining brown epidermis passing over the edges of the 

 valves, invariably pertains to the inequivalve, inequilateral, 

 transverse, and oblong shell of the Solemija. This elegant 

 shell is obtuse at the extremities : it possesses a cardinal 

 tooth in each valve, and a callosity, running between them, 

 receives the ligament which is seen both internally and 

 externally. 



Sowerby created the genus Solenella for the intro- 

 duction of a new and interesting moUusk, brought from 

 Valparaiso by Mr. Cuming. The shell partakes of the 

 characters of both Solecitrtus and Nucula, having an ex- 

 ternal hgament and large sinus in the muscular impression, 

 as in the shell of the former; and a lateral row of sharp- 

 pointed teeth, as in that of the latter, though chiefly on the 

 posterior side. 



The Glauconomes are of a Kght semi-pearlaceous structure. 



