77 



ENSIS, Schumacher. 



Gen. Char. Equivalved, very inequilateral, trans- 

 verse, slightly arched ; gaping at both ends^ 

 margins parallel, umbones close to the anterior 

 extremity. Hinge with one conical erect tooth 

 in the right valve, and two compressed erect 

 teeth in the left valve, and an elongated trans- 

 verse lateral tooth, connate with the fulcrum, 

 and the erect teeth, in each. Muscular impres- 

 sions, &c. as in Solen. 



Ihe presence of the long lateral teeth in the hinge is so 

 strong a character, that we cannot avoid adopting Schu- 

 macher's genus. We are not prepared to say it is positively 

 a natural genus, but most, if not all, of the species are a 

 little arched, and none of them have the anterior side de- 

 fined by a furrow, which is so often the case in Sole7i : these 

 general relations, although slight, have some pretensions to 

 natural characters; moreover, the long lateral teeth, whose 

 office is to steady the valves when they open, must have 

 reference to some habits of the animal in which it differs 

 from Solen. Solen Ensis of Linnaeus is the type of the 

 genus ; it includes also S. siliqua, and a few others. 



ENSIS ensiformis. 



TAB. DCXLII.— ^g-. 1. 



Spec. Char. Gently curved, thin, smooth, con- 

 vex, about four times as wide as long, the two 

 angles of the posterior and the lower angle of 

 the anterior extremities rounded ; the poste- 

 rior portion a little flattened ; the basal edge 



