55 



CHAPTER IX. 



OF THE TELLINA. GENUS VI. 



TELLINA. 



" Animal a Tethi/s. Shell bivalve, the fore part folded from one side to the 

 other ; hinge with three teeth, the lateral ones flat in one shell." — Linn. 



X HIS genus is not so well defined as many others. Linnaeus 

 says, " hinge with three teeth ;" he also says the same of the 

 Venus. The Tellince have generally two hinge teeth in one 

 valve, and one in the other valve ; but some species have more, 

 and some have less. The animal is a species of Cockle, having 

 the mantle or pallium open or divided in front, projecting two 

 distinct short tubes fi*om one end, which in most species reach 

 but just beyond the margin of the shell, and a scythe-shaped 

 muscular foot from the front. Linnaeus calls it a Tethys ; so 

 also he does the Oyster, from which it differs much. The 

 Tellina, like all the Cockles, has two muscular impressions on 

 the inner surface of each valve : but the Oyster has only one. 



The teeth in the different species vary so much that it is very 

 difficult to know which shells are Tellina and which are not. 

 Perhaps Linnaeus might rely principally on the fold-like ap- 

 pearance towards the pointed end or fore part, which is seen 

 in many of the species, for determining this genus ; but still 

 he has admitted many wliich are destitute of it, as Tellina reti- 



