46 MY A. 



Inhabits the shores of Devonshire, burrowed in old oyster 

 shells. Montagu. 



The length, which is somewhat exceeded by the breadth, is 

 about one eighth of an inch, and the colour dirty white ; in 

 one valve there are two broad flat distant diverging teeth, but 

 the other valve is toothless, and has only a small cavity under 

 the beak. 



decussata. 12. Shell ovate, with irregular con- 

 centric ridges, and longitudinal striae form- 

 ing tubercles at the anterior end ; margin un- 

 dulated. 



Mya decussata. Montagu Supp. p. 20. t. 28. f. 1 . Wood's 

 Conch, p. 99. 



Inhabits the Frith of Forth. Montagu. 



Shell white, nearly half an inch long, and the breadth rather 

 exceeds the length ; the muscular impression is shaped like a 

 tongue, and one valve has a broad erect tooth, which is fitted 

 to a projecting indented plate in the other. Mr. Montagu 

 says, that in its irregular growth and general appearance, it 

 somewhat resembles a variety of Donax Irus. 



purpurea. 13. Shell ovate, transversely wrinkled ; 

 hinge with an erect slightly bifid tooth in 

 each valve. 



Mya purpurea. Montagu Supp. p. 21. Wood's Conch. 

 p. 100. 

 Inhabits the coasts of Devon amongst corallines in deep water. 



Montagu. 

 Shell scarcely one line long, and but little more in breadth, of a 



purple colour, becoming white towards the margin. 



ferruginosa. 14. Shell sub-ovate, obsoletely wrin- 

 kled ; hinge with two projecting teeth, sepa- 

 rated by a large triangular notch. 



Mya ferruginosa. Montagu Supp. p. 22. t. 26. f. 2. Dor- 

 set Cat. p. 28. Wood's Conch, p. 100. 



Found on Belton Sands, near Dunbar. Montagu. 



Shell about a quarter of an inch long, and nearly twice as broad ; 

 it is moderately convex, and has the beak obtuse, and placed 

 nearer to one end than the other ; of the two teeth one is 

 erect, and the other turns inwards, and slopes downwards. 

 Mr. Montagu says it is usually covered with a thick tenacious 



