152 The Museum Gazette 



1 



Fig. 20. Akera bullata. Very thin, elastic, horn colour. 



Figs. 21, 22. CypYcea eiwopcea (= Trivia envopaa). The only 

 European cowry. Pale livid rlesh colour, sometimes pure 

 white on the base. Immature specimens are not nearly so 

 common as full-grown ones, they were mistaken by old writers 

 for a Bulla, and they somewhat resemble a Succinea, being 

 white very fragile and pellucid, and having a short blunt 

 spire of two or three whorls. 



Univalves. 

 Description of Plate II. 



Fig. 1. Patella athletica. Surface ribbed. It differs from 

 the common Limpet (P. vulgata) in the tooth-like scales 

 arming the ribs. 



Fig. 2. Patella pelliicida (= Patina pellucida). Surface 

 smooth or nearly so, usually with bluish-green linear mark- 

 ings radiating from the centre. Concerning the variety Icevis, 

 we quote the following interesting particulars from Forbes 

 and Hanley, vol. ii., p. 430 : " The two varieties of this 

 elegant limpet differ so remarkably from each other, as 

 strikingly to illustrate the effects of food and habitat upon 

 colour and solidity. The more typical pellucida feeds upon 

 the leaves of the Fuci, the aberrant Icevis upon the roots and 

 stalks, in which indeed it is wont to imbed itself. The former 

 is thin, semi-transparent, of a dark olive when adult, of an 

 ochraceous yellow when young, is regular in shape, which 

 ranges from subelliptic to rounded ovate — for, as in most 

 limpets, the shape tapers a little behind, and is adorned with 

 more or less interrupted linear rays of lustrous mazarine blue, 

 that vary greatly both as to number and approximation. The 

 latter form is a much stronger shell, very irregular in shape, 

 yet generally pinched up, as it were, at the sides (so that 

 when placed upon a level surface, the side margins alone 

 touch it), of a yellow or ochraceous horn colour, with the blue 

 rays often all but wholly obsolete, and almost invariably of 

 a lighter tint." 



