202 



pression. No depression or groove in front of the columella. Colu- 

 mellar side more gibbous than the outer, and the ribs continue en- 

 tirely round it, converging towards the centre. 



Length -300 of an inch; breadth -200; height -175. 



Habitat. Isle of Muerte, Bay of Guayaquil. 



Nearest in shape to Cypr. exigua, and in the manner of the ribs 

 terminating on the back ; but it is of a dull white colour, destitute of 

 markings, and has no groove or depression in front of the columella, 

 which distinguishes it from all other species of this form of Cypraa. 



Cab. Cuming. 



I had the misfortune to break the only specimen that I have seen 

 of this shell shortly after I had described it, but having submitted 

 the description to the critical examination, with the shell, of Dr. 

 Beck and Mr. Sowerby at the same time, I conclude this description 

 may be received, although I have no specimen to show to the So- 

 ciety. 



CTPRiEA Pediculus, var. labiosa. Cypr. testd ovali, laid, extremi- 

 tatibus rotundatis ; costis prominentioribus, nullis supra labium 

 externum terminantibus ,• marginibus latioribus, crassioribus ; lined 

 dorsali profundiore, fused ; basi marginibusque cinerascenti-gri- 

 seis ; dentibus albis. 



Shell oval, of a reddish brown on the back, running into a blueish 

 brown on the sides ; six rather large dark brown spots on the back, 

 three on each side the dorsal line, placed opposite to each other at 

 the anterior, middle, and posterior parts of the back ; base of a grey- 

 ish brown colour, rounded and broad. Aperture rather wide, white 

 within : teeth about twenty on the lip, white, prominent, even and 

 distant, and all continuing evenly over the lip forming the ribs, 

 several of which terminate on the side of the shell, the others (about 

 twelve) at the dorsal line, in elevated and broad or thickened ends ; 

 on the columella there are about fifteen teeth, a few of which, con- 

 tinuing to form the ribs, terminate on the side of the shell, the rest 

 at the dorsal depression, in a similar form to those on the opposite 

 side ; there are about two floating ribs, false ribs at each end. Colu- 

 mellar groove very shallow posteriorly, rather deeper and wider an- 

 teriorly ; the teeth passing, slightly prominent, across it form a ser- 

 rated edge at its inner border. Margins much thickened and pro- 

 duced, terminating in a coronated ridge aU round the shell, scarcely 

 more prominent at the extremities than on the outer or lip side. 

 Extremities round. Dorsal line rather broad, deep, shining, and of 

 a darker brown colour than the back. 



Length -525 of an inch; breadth -410; height -320. 



Habitat. 



Differs from Cypr. Pediculus in being broader and shorter, and 

 rounder at the extremities ; in the colour and shape of the base ; 

 in having much more prominent ribs, and none terminating on the 

 lip ; margins infinitely thicker and broader ; teeth white ; dorsal line 

 more impressed, &c. 



Cab. Gaskoin. 



