136 



poda, and only differs from the two others of this fa- 

 mily, in consequence of the shell not being affixed by 

 a pedicle. This genus is evidently confounded by La- 

 marck with that of Crania, as has been satisfactorily 

 stated in the description of that genus given by Sower- 

 by, in No. 12 of his Genera of Shells. 

 Orbicula Norwegica. 



TEREBRATULA. 



ANOMIA VITREA. Linil. 



Sowerbys Genera, No. 1 5, plate 2. 

 The necessity of separating this genus from that of the 

 G. Anomiaof Linnaeus, was observed by Bruguiere, and 

 is manifest on an inspection and comparison of the two: 

 there is no general resemblance between them, and the 

 animals of each are very differently organized. The 

 shell of the Terebratula is inequivalve, of a subovate 

 form, and is attached to marine bodies by a short fleshy 

 tendinous peduncle terminating in a number of byssi- 

 form filaments passing through the hole, or sometimes 

 only sloping cleft, at the summit of the recurved beak 

 of the larger valve, and by which the shell is suspend- 



