MYTILUS MUSCLE. 183 



ANOMIA Psittacea* 

 PARROT BEAK ANOMIA. 



Specific character. Shell oval, horny, pel- 

 lucid ; the beak much produced, curved, and 

 perforated, the hole subtriangular ; margin sinu- 

 ated, entire ; surface finely striated longitudinally; 

 colour is blackish, or greenish brown ; length 

 about three-quarters of an inch exceeding the 

 breadth. 



This shell belongs to the Terebratulae : it 

 inhabits the Indian Sea and Greenland, 



GENUS. MYTILUS.t 



MUSCLE. 



Generic character. Shell bivalve, rough, gene- 

 rally affixed by a byssus to marine substances ; 

 hinge mostly without teeth, marked by a furrow 

 or subulate line excavated longitudinally this 

 line is crenated in some of the species ; shape 

 generally a long oval, sometimes lobed, some- 

 times elongated at the beaks. 



BSERVATIONS ON THE SHELL AND ITS 

 INHABITANT. 



Though all the Mytili are not inseparably 

 attached to other substances, all are by some 



* Plate IX. figure 9. f Plate X. figure 2. 



