17 



II. ANODON. 



Shell bivalve, transverse, equivalve, inequilateral, a 

 little open at the sides. Hinge without primary 

 teeth, or with a small obtuse tubercle : lateral tooth 

 a transverse elongated lamina under the ligament 

 on the anterior side, terminating in a deep depres- 

 sion. Ligament external. 



8, ANODON cygneus. Shell oval, tumid, arcuated at 

 the front margin, with the anterior side more or 

 less angular when young, and gradually sloping to 

 a point when full grown. 



Anodon cygneus. Turton's Bivalves, t. 15. f. 5. 

 Anodonta cygnea. Drap. t. II. f. 6. 

 Mytilus cygneus. Montagu, p. 170. 

 Young. Anodon anatinus. Sonerby, Genera. 

 Anodonta anatina. Drap. 1. 12. f. 2. 

 Mytilus anatinus. Montagu, p. 17 1. 



Shell growing to nearly three inches long, and above 

 six wide, green, pale brown or fawn-colour, often 

 radiated, striate or wrinkled transversely, covered 



