48 MYA. 



## 



Hinge callous ivithout Teeth. 



edentula. 18. Shell oval striated, with equal 

 valves, forming a large hiatus ; hinge without 

 teeth. 



Mya edentula. Pallas Itin. ii. p. 700. Chemnitz, vi. p. 35. 

 Gmelin, p. 3220. Wood's Conch, p. 96. 



Inhabits the sandy shores ot' the Caspian Sea. Pallas. 



Shell about an inch long, thin, white, somewhat grooved trans- 

 versely, and marked with about thirty-three striae on each 

 valve, which are more distant at the narrower than at the 

 broader end ; the hinge has a thick reflected lip. 



membranacea. 19. Shell oval, membranaceous and 

 white; one side is extended so as to form a 

 beak, and has the margin reflected; hinge 

 toothless. 



Mya membranacea. Olaffsen Isl. Res. ii. p. 1009. t. 11. 

 f. 10. Chemnitz, vi. p. 6. Gmelin, p. 3222. Wood's 

 Conch, p. 98. 

 Inhabits the coast of Iceland. Olaffsen. 

 This shell is described to be oval, about the size of a bean, and 

 to have a plain hinge, without any appearance of teeth. 



norwegica. 20. Shell oval, closely striated longi- 

 tudinally, rounded at one end, and truncated 

 at the other, with the beaks decorticated. 



Mya Norwegica. Chemnitz, x. p. 345. t. 170. f. 1647. and 

 164S. Gmelin, p. 3i22. Wood's Conch, p. 98. t. 18. 

 f. 4 and 5. ? 

 Mya nitida. Mailer Zool. Dan. Prod. n. 2963. Gmelin, 

 p. 3222. Wood's Conch, p. 103. ? 

 Inhabits the coasts of Norway. Chemnitz. 

 Shell near an inch long, and an inch and three-quarters broad, 

 of a dirty white colour. Mr. Wood says the inside is pearly, 

 and that there is a triangular piece, resembling enamel in the 

 cavity of the hinge, which, unlike a regular tooth, does not 

 appear to be permanent. — Mr. Wood also says, that when 

 the shell is stripped of its epidermis, the longitudinal strize are 

 hardly visible, and in this state it answers tolerably well to 

 the Mya nitida of Muller. 



