PROSOBRANCHIATA. 125 
water. This subdivision, although very convenient, is not, as Mr. Woodward* remarks, 
altogether satisfactory ; inasmuch as several genera occur among the Aolostomata 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 Lovén 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 
paleontologist. 
Family—Cy PREID&. 
Genus 20th. Cypraa.t Linn. 1740. 
Peripoivus, Adanson, 1757; De Blainville, 1825. 
Cyprma, Lamarck, 1801; De Blainville, 1825. 
Cyprea, Monftf., 1810. 
CoccinEeLta, Leach, 1820. 
Trivia—CyprovuLa—Lvponia, 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 Cyprza 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. 
+ Etym., from Cypris, one of the names of Venus. 
