PROSOBRANCHIATA. 1 25 



water. This subdivision, although very convenient, is not, as Mr. Woodward* remarks, 

 altogether satisfactory ; inasmuch as several genera occur among the holostomata in 

 which the proboscis is retractile, or the shells are notched or furnished with an anterior 

 canal. 



By far the greater part of the present order are furnished with an operculum, but 

 many are without that protection. 



Since Loven published the result of his examination of the dental apparatus of 

 Mollusca, much attention has been paid to the subject, and great importance is attached 

 to the condition of the lingual teeth. But the assistance derived from this character, 

 however valuable it may prove to malacologists, can be available indirectly only to the 

 palaeontologist. 



Family — CypRjEidjs. 

 Genus 20th. CypRiEA.f Linn. 1740. 



Peribolus, Adanson, 1757 ; De Blainville, 1825. 



Cyprjea, Lamarck, 1801 ; Be Blainville, 1825. 



Cyprea, Mont/., 1810. 



Coccinella, Leach, 1820. 



Trivia — Cyprovula — Luponia, Gray, 1830. 



Gen. Char. — Shell oviform, oblong or sub-globular, convolute, enamelled, generally 

 smooth, sometimes pustulous, transversely ribbed, or cancellated : spire short, depressed 

 visible only in the young state, when adult, concealed by the enamel ; aperture long, 

 narrow, terminating at each extremity in a short canal ; outer lip inflected, crenulated ; 

 inner lip crenulated. 



The animal of Cyprsea has a broad, sub-lunate head, terminating in a short retractile 

 muzzle, and bearing long subulate tentacles on bulgings, at the outer bases of which 

 the eyes are placed. The foot is broad, truncated in front, pointed, and sometimes 

 much produced behind ; the mantle terminates in a siphon in front, and the lateral 

 margins, as the animal approaches maturity, expand into lobes, generally equal, 

 but frequently more or less unequal, and which can be extended at pleasure, so as 

 entirely or nearly to cover the shell, the edges meeting on the back or on the right 

 side, according as the lobes are equal or unequal. By these lobes is deposited the 

 testaceous matter which forms the enamel-like covering of the shell, characteristic of 

 the family ; the line of juncture being usually indicated, in recent cowries, by a groove 

 or a streak of a fainter colour. The outer surfaces of the lobes are generally covered 



* 'A Manual of the Mollusca,' p. 122. 



t Etym., from Cypris, one of the names of Venus. 



