ANATINA. 



TESTA transversa, libera, insequilateralis, ple- 

 rumque inaeqiiivalvis ; utroque latere hiante : 

 plerumque processu parvo, cochleariformi, 

 ligamentifero in utraque valva et appendiee 

 testacea, curva, parva, interdum minima, ante 

 processus ligamento connexa. 



Apparently related to Mya in the habits of the animal, 

 as well as in the general characters of the shell, but well 

 distinguished from it, by its having a moveable testaceous 

 appendage connected with the ligament immediately 

 before the hinge teeth. It is observable that Lamarck, 

 who established the Genus, should not have mentioned 

 this singular appendage, of course founding its claim to 

 generic distinction upon the difference of form and posi- 

 tion of theligamentiferous processes; this little appendage 

 is, however, in some species so small, and in general so 

 deciduous, that it is not surprizing Lamarck should not 

 have noticed it — the specimens which he had the oppor- 

 tunity of examining having probably lost it. We must 

 not here omit to notice that Lamarck's jlmphidesma 

 corhulo'ides belongs to this Genus : it is the Mya norvegica 

 of authors, and the Li/onsia striata of Turton. 



Thei'e are so many differences in the characters 

 peculiar to each species, which may, without impropriety 

 be united under the generic appellation of Anatina of 

 Lamarck, that it is difficult to find any set of characters in 

 which they generically agree ; in some species the valves 

 are both equal, in others they are unequal; in some there 

 is a distinct spoon-shaped process to which the ligament 

 is attached, in others this process is much less evident, 

 while there are several in which it does not exist at all; 

 in some the accessory, internal, testaceous, appendage (the 



