Tusk-shells, Mail-shells, and Limpets 



185 



The girdle is evenly covered with minute granules, 

 vari-coloured, and fringed with short yellow spines. 

 It is one of our counnonest forms, and 

 may be found everywhere under stones 

 at various depths, even above ordinary 

 low- water mark. It is represented of 

 the natural size in our figure. The Red 

 Mail-shell (C. ruber) is much like C. 

 margined us, but more slender, more 

 convex, of a reddish-brown tint, and presenting a 

 smooth appearance. The girdle, too, is broader, and 

 chequered with small patches of red and white. It 

 is a species of general distribution on our coasts, 

 from low water to a depth of 20 fathoms, where it 

 may be found on rocks, stones, and at the base of 

 the Laminar ias. 



The Smooth Mail-shell {C. Icevis) is convex, broad, 

 and glossy, marked with microscopical scratches and 

 minute tubercles. It is reddish brown in colour, 

 veined with white, or variegated with 

 green or pink. The head-plate has from 

 16 to 20 deep notches, the tail-plate 15, 

 and the others 2 each. The broad girdle 

 is covered with small spine - like scales, 

 their tips towards the margin, which is 

 thinly fringed with short pink spines that 

 readily fall off. The animal is about an 

 inch long. It is widely distributed, and extends 

 from extreme low water to about 70 fathoms. The 

 Marbled Mail -shell {C. niarmoreus) is the largest 

 of the British species. It has a broad glossy shell, 

 almost smooth to unassisted sight, but under a lens 

 showing many minute tubercles; coloured witli red- 



