244 G O N C H O L O G Y. 



S E G T I O N XII. 

 Division II. Bivalves. 



P 



ART I. Shells that have unequal 

 valves, and (hut clofe. 



Family I. Peftens orEfcallops. Though 

 fome fpecies of this family have equal 

 valves, yet, as the far greater number 

 have unequal valves, to wit, a flat and a 

 concave, I range them under this part. 

 The fame particular likewife occurs in the 

 families of the Spondyles and Oyfters. 



The head or eflential charafler of the 

 Efcallop family, is a trigonal finus. PL 

 VI. fig. I. a. and an elaftic cartilage for 

 its hinge in the very center of the top of 

 the Shell. 



The 



