JVedge-shells^ Venus-shells^ and Cockles 1 2 7 



Cut Trough-shell 



both before and behind the beaks. The animal lias 



the mouth of its siphon-tubes fringed with two rows 



of yellow or red filaments. The 



foot is yellowish and slender ; the 



mantle with a toothed edge. It 



lives in coarse sand from low water 



to 27 fathoms. In the north of 



Ireland it is known as Lady Cockle ; 



in the Clyde district it is the "Aikens." 



The Rayed Trough-shell {M. stultorum) is of the 

 same general shape as M. sol Ida, but thin and glossy, 



and the yellowish ground is 

 largely covered by broken 

 ra^^s of brown from the 

 beaks to the margin. The 

 animal is white, tinged with 

 blue ; the mantle fringed 

 with white filaments ; the 

 foot white, thick. It is 

 common on all our shores, 

 the animal burrowing in sand between extreme low 

 water out to 18 fathoms. The Glaucous Trough-shell 

 (M. glauca) is triangular-oval, rather thin and glossy ; 

 yellowish white, witli rays of yellow-brown or fawn 

 colour, and the upper margins marked with brown. 

 It is covered with a brown, satiny epidermis. The 

 animal is white, its mantle fringed with white fila- 

 ments : the siphon-tubes short and conical, tinged 

 with 3^ellow and streaked with red-brown. It is a 

 rare species, but it occurs on the Cornish coast, 

 where it ranges over the sand in shallow^ water, 

 quickly burying itself to a depth of two or three 

 inches when the tide goes out. 

 9 



Rayed Trough-shell 



