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ANOMIA; Linn. 



Gen. Char. An irregular bivalved Shell : with 

 a foramen in the flatter valve that allows the 

 passage of a bony appendage by which the 

 Animal is attached to marine substances; 

 beaks none or very short. 



All the species of this genus have one valve nearly 

 flat, and exactly conforming to the surface it is applied 

 to and where it is fixed by the bony appendage termina- 

 ting one of the muscles that is united to the other valve : 

 this appendage is often termed an operculum ; it exactly 

 closes the hole in the valve it pervades, which can never 

 be opened by the animal, since the convex valve is the 

 only moveable one : the hinge is a small ligament con- 

 tained within the beak of the convex valve, and attach* 

 ing the margin of the other to it. The convex valve 

 alone may be known by three approximating muscular 

 impressions nearly in the centre of it. 



This Genus is so easily recognized, that it is remark- 

 able Linneus should have comprehended the modern 

 Genus Terebratula with'it. It is unfortunately named. 



