156 CONCHOLOGY. 



dified by the turn of the summit, and provided on each side with 

 an ear-like appendage having thick and smooth edges. Inhabits 

 the Mediterranean. Three species. 



Argonauta argo. Argonauta tuberculosa.' 



A. nitida. 



2. Genus Carinaria. PI. XII, 



Animal. Body elongated, prolonged behind the nucleus into 

 a veritable tail, edged at its extremity by a vertical fin ; head suffi- 

 ciently distinct ; two, long, conical tentacula; two sessile eyes ; the 

 organs of respiration and the nucleus entirely enveloped in a 

 mantle with lobed edges. 



Shell. Very thin, symmetrical, a little compressed, without 

 spire, but with the sumnit a little reflexed posteriorly ; aperture 

 oval and entire. Inhabits the African, Mediterranean, and Aus- 

 tralian seas. Three species. 



Carinaria vitrea. Carinaria fragilis. 



C. cymbium. 



