21 



Mysca Pictorum. Turton, Dith. p. 245. 

 Unio Pictorum. Drap. 131. t. 11. f. 14. 

 Mya Pictorum. Linn. Gmelin. 



Wood, p. 104. t. 19. f. 3, 4. 

 Mya ovalis. Montagu, p. 34. 



Shell an inch and a quarter long, and nearly three 

 inches broad, narrow oval, covered with a yel- 

 lowish-green skin ; a little flexuous at the anterior 

 side, and slightly contracted at the front margin ; 

 inside perlaceous or pale fawn-colour. 



In most clear rivers. 



12. MYSCA ovata. Shell oval, tapering to the an- 

 terior end, with the front margin slightly arcuated 

 or contracted ; beaks wrinkled. 



Mysca ovata. Turton, Dith. p. 246. 

 Mya ovata. Wood, p. 105. t. 19. f. 5. 

 Mya ovalis. Montagu, p. 563. 

 Mya depressa. Donovan, iii. 1. 101. 



Shell an inch and a half long and two and a half 

 broad, covered with a brownish-green skin, often 

 radiate, rather depressed; the anterior end fre- 

 quently slightly falcate. 



In the Thames, the Avon, and the Froome. 



