GLYCIMERIS. CONCHIFERA. Jll 



valve. The point of union of the valves at the place of the hinge varies also much 

 according to the species. The Solenides live in the sand, which they perforate by 

 means of their subcylindrical long foot. The lobes of the mantle are united before, 

 and open at the two extremities. 



Gen. 50. GLYCIMEKTS, Lam, Mya, Chem. 

 Shell transverse, gaping widely on each side ; hinge callous, 

 without teeth ; ligament exterior. 



G. siliqua t 'La'm. Shell thick, strong, gaping at both ends, and covered 

 with a black epidermis ; inside bluish white, with testaceous ex- 

 crescences; umbones decorticated. About an inch long, and nearly 

 thrice as broad. Northern seas Chem. pi. 198, tig. 1934. 



G. arctica, Lam. Shell ovate, ventricose, truncated before, trans- 

 versely striated, with two obtuse ribs. Inhabits Arctic seas. 

 Lam. v. 458. 



Gen. 51. PANOPEA, Lam. 



Shell equivalve, transverse, gaping unequally on the sides ; one 

 primary conical tooth in each valve, and a compressed, short, 

 ascending callosity on one side ; ligament exterior, on the 

 elongated side of the shell, fixed upon the callosities. 



P. Aldrovandi, Lam. Mediterranean sea. I Aster, pi. 414, fig. 258. 

 A fossil Panopea was found near Parma in Italy. 



Gen. 52. SOLEN, Lam. Lin. 



Shell bivalve, equivalve, elongated transversely ; gaping at both 

 ends ; primary teeth small and in variable number, sometimes 

 none ; ligament exterior. 



The animal of this genus has the mantle united before ; and projects at one end of 

 the testaceous tubes a subcylindrical foot, and at the other two tubes in a common 

 envelope. The Solenes live in sandy shores, and their place is distinguished by a hoi- 

 low opening in the sand. When alarmed they descend much deeper ; and it is said 

 that they are sometimes induced to project their shell to the surface by sprinkling a 

 little salt on their hole. 



* Hinge terminal ; the anterior extremity truncated. 



S. vagina, Lin. Shell linear, straight, margined at one end ; hinge 

 with a single opposite tooth in each valve at one end; colour orange 

 yellow or brownish, marked with striae, which change their direc- 

 tion from transverse to longitudinal. f inch long, and four inches 

 broad. Indian and European seas. B Wood's Coc/.pl.27,fig. 1. 



S. siliqua, Lin, Shell linear, straight ; hinge terminal, with a double 

 tooth in one valve ; one with a remote lateral lamina in the other; 

 epidermis greenish brown, striated transversely on one part and 

 longitudinally on the other. 1 inch long, and 8 inches broad. 

 Inhabits European coasts. B. Wood's Conch, pi. 26, fig. 1 and 2. 

 Very common. It is dug for sale as food. 



S. ensis, Lin. Shell linear, somewhat curved ; hinge with a double 

 tooth in each valve. J inch long, and about 5 inches broad. In- 

 habits coasts of Europe. B Wood's Conch, pi. 22, fig. 1, 2. 



The old shell is of a brownish green colour ; but young shells are thin, brittle, 

 . and prettily mottled with brown and green. 



