100 GENUS XXI. CYPR^EA. 



and Murices ; for in the Cyprcece the small siiells are always 

 found as complete, /. e. with the aperture or mouth as perfectly 

 formed as the larger ones of the same species. 



There are sometimes found some very thin shells with a 

 twisted pillar, a little resembling- in shape Bulla Ficiis (^pl. j. 

 /. 61. c) ; these are suj)posed to be the young and imperfectly 

 formed shells of the Cyprcea soon after casting tlie others, and 

 to have been mistaken sometimes by authors for a distinct 

 species : perhaps Conns bullatus of Linnaeus is one of these. 

 Adanson describes one (p. 73) somewhat similar, which he 

 calls Potan ; he says it is the most thin and brittle shell of any 

 tliat is found in the sea ; he describes the animal as resembling 

 the animal of the Cyprcea, but not as being the same ; he also 

 says it is somewhat like the animal of Valuta glabella, &c. ; 

 but he seems not to know, or even suspect, that the Cyprcece 

 change their shells. More information on this subject is much 

 to be desired, particularly as this circumstance is not known 

 or supposed to take place in any other genus of shells. 



This genus is very distinct from every other. The essential 

 character is the aperture toothed on both sides, with a liollow 

 at each end. 



The animal is a kind of Snail with two horns Qpl. 5. /. 61. a), 

 Avhicli are somewhat conical, tapering to a very fine point ; 

 they are about one-third as long as the shell ; the eyes are on 

 the exterior side, at about one-fifth of their length from the 

 base ; the breathing tube is very short, not extending beyond 

 the shell (/)/. 5. ./'. 61. a) ; but what is most remarkable is a 



