54 THE ELEMENTS 



C oval, a little anp^ular near the beaks. 



Habitation. The shells of this ge- 

 nus have only been found to inhabit 

 the ocean. They in o^eneral lurk in 

 the sand ; and many of the larger spe- 

 cies are only to be found in very deep 

 water. 



The shells composing this numerous 

 tribe, are perhaps the most elegant, 

 and beautifully diversified, of all the 

 bivalve shells. 



In Turton's Linne, no less than 154 

 species are described ; and 25 species 

 have been discovered to inhabit the 

 seas around Great Britain. 



Genus 1 1th.— SPONDYLUS. Ani^ 

 mat a Tethys : shell hard, solid, and 

 ridged, with unequal valves ; one valve 

 in general convex, and the other ra- 

 ther flat: hinge with two recurved 

 teeth, separated by a small hollow, 

 Linn. Syst. 310. Plate 6th, fig. 11th. 



Habitation. This genus has only 

 been found to inhabit the ocean. They 



