CONCHOLOGY. 39 



plete.; similen formed by a conical primary tooth, before a short, 

 compressed, ascending callosity, ligament exterior, attached to 

 the callosity ; two muscular impressions. Inhabits the Mediter- 

 ranean Sea. One species. 



Panopsa Aldrovandi. 



3. Genus Solecurtiis. PI. VI. 



Jinimal. Unknown. 



Shell. Oval, elongated, equivalve, subequilateral, with edges 

 nearly straight and parallel, the extremities equally rounded, and, 

 as it were, truncated ; summits but little marked ; hinge without 

 teeth, or formed by some rudimentary primary teeth, ligament pro- 

 jecting, affixed to thickened callosities ; two distinct rounded mus- 

 cular impressions. — Mediterranean Sea and coasts of America. 

 Ten species. 



Solecurtus radiatus. S. strigilatus. S. legumen. 



S. fragilis.* S. lucidus.* 



S. costatus.* S. Nuttallii.* 



S. Caribaeus.* S, subteres.* 



S. Californlanus.* 



4. Genus Glycimeris. PI. VI. 



Animal. Unknown. 



The few species of this genus yet known have been blended, 

 by previous authors, either with the Mya or Solen, but from 

 either they are easily distinguished. 



Shell. Covered with epidermis, slightly irregular, elongated, 

 gaping at both ends, equivalve, exceedingly inequilateral ; sum- 

 mits little marked; hinge toothless; a longitudinal callosity. 

 Ligament exterior, affixed to very projecting callosites on the 

 shortest side of the shell ; two distinct muscular impressions. In- 

 habits the North seas. Two species. 



Glycimeris margaritacea. Glycimeris siliqua. 



