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



This family has not many fpecles. 



To this family of Arks I imagine the 

 foffil Hippocephaloida belong, and that they 

 are fpecies of it, yet undifcovered recent 

 or living from fea : my reafon for rank- 

 ing them with the Arks, and not the 

 Cunei, is, that they appear to me to be 

 multarticulate Shells. 



Part II. Seft. 2. comprehends all Bi- 

 valves with equal valves, that are not eared, 



and have few teeth upon their hinge. 



This fe£lion is extremely numerous, and 

 very confufed in authors. I (hall there- 

 fore proceed firft with the eighth family of 

 Pe6lunculi or Cockles, whofe charadler is 

 a curved or femilunar hinge fet with two 

 to four ftrong teeth. PI. I. fig. 8, 9, 14, 

 PI. VI. fig. 8, 12. PI. VII. 1,2,3, 10,11. 



This family of Cockles is fo extremely 

 numerous, and befides has fuch ftriking or 



remarkable 



