MAEGINELLA. 205 



with the lobes of his mantle ; in other respects he resembles 

 Cijpr(Ba. 



0. patula is whitish^ having the mantle tinged with yellow 

 and barred with orange stripes, and covering two-thirds 

 of the shell, which is open, with a peak or rostrum at 

 both ends ; white, smooth, and without any visible spire. 

 0. acuminata is named from a very little, white, narrow, 

 bulla like shell, peaked at the back, rounded in front. 

 It is a very rare shell, and uncertain as to its real cha- 

 racter and position, for the animal is not known. 

 III. Marginella lavls is the only British representative 

 of a most beautiful race of moUusca, with highly enamelled, 

 poKshed shells. The siphon, the tentacles, the square-fronted, 

 sharp-cornered foot, the eyes near the base of the tentacles, 

 and the mantle covering the greater part of the shell, are all 

 present, as in the animal of C^j^rcea JEuropma; but the foot 

 is shorter, the head much more produced between the ten- 

 tacles. The mantle is covered with little swellings, and is 

 speckled with black, yellow, and brown. The shells of the 

 Mar(jinell(2 are polished, and show their spires, although 

 they are small, and the sutures covered by an enamel. M. Imvis 

 is rather conical, and has the outer lip thickened, inflected, 

 and crenulated. 



