SOLENACEA. MOLLUSCA. SOLEMYA. 35 



in such a manner as to form three radiated compartments of each 

 color. There are minute wrinkles about the posterior extremity, 

 and minute series of them across the middle of the shell, arranged 

 so as to appear like radiating lines. Within livid, and somewhat 

 iridescent. Rib white, inclining backwards, and extending, about 

 two thirds across the valves. Teeth as in the preceding species, 

 excepting that the branch of the bifurcated tooth is less prostrate. 

 The same remark as to their deficiencies applies to this species as 

 to the other. Height inch, length ^ inch, width T \ inch. 



Found abundantly upon every sandy beach, and probably 

 inhabits the sand in shallow water. It is one of our most beauti- 

 ful shells. It is much more delicate and smaller than M. nitidus. 

 The radiations of color are evident, but have no very distinct 

 dividing lines ; a whitish, narrow ray, running obliquely backwards, 

 and another answering to the interior rib, are generally conspicu- 

 ous. The colors are also arranged in zones, as well as rays. 



GENUS SOLEMYA, LAM. 



Shell equivalve, inequilateral, transverse ; epidermis thick and 

 shining , projecting far beyond the margin ; beaks inconspicuous ; 

 hinge margin widened and excavated to form a receptacle for a 

 cartilage, usually resting on a rib-like support. 



SOLEMY'A VELUM. 



Shell oblong, very thin and fragile ; epidermis pale yellowish- 

 brown, marked with radiating lines ; within purplish-white ; car- 

 tilage-support arched, the points directed across the shell. 



State Coll., No. 222. Soc. Cab., No., 1738. 



Solemy^a velum, SAY ; Journ. Acad. Nat. Sc. } ii. 317. 



Shell remarkably thin and fragile, transversely oblong, rather 

 broadest behind ; very inequilateral, upper and lower margins 

 nearly parallel, ends rounded ; beaks in no degree elevated, but 

 having a slight pit in front of them ; surface of the valves radiated 

 with about fifteen slightly impressed, double lines, most conspicu- 

 ous posteriorly, and most widely separated across the middle ; 

 short end distinctly wrinkled by the lines of growth ; epidermis 

 light yellowish-brown or chestnut-color, firm, elastic, glossy, at 



