GASTROPODS. 
383 
The fig-shells JPirula) have an extensive foot, like Dolium, hut the mantle is 
largely lobed on each side, and reflexed upon the shell. This is of an elongate pear- 
shape, with a short spire and a long canal, and has the surface transversely 
striated or ridged, or more or less cancellated. There are nine recent species 
belonging to this genus, which is also found fossil in the Chalk and Tertiary 
deposits. The genus is included in the Doliidce. 
fig-shell (Pirula ventricosa ), from above and beneath (nat. size). 
The cowry, or, more properly, kauri shells ( Cyprceid.ee ), are so well known 
that a description is scarcely necessary. They are all formed much after the 
same pattern, and are almost always coated with a brilliant enamel, caused by the 
lateral lobes of the mantle being reflexed upon the shell. In the young the shells 
exhibit a short spire, which in the course of growth becomes entirely or almost 
concealed. Many of the shells are exceedingly beautiful, and some of the animals 
are even more brilliantly coloured. The cowries have no operculum, but a large 
foot, and can retract their bodies entirely within the shell, notwithstanding the 
narrowness of the aperture. The shells, as is well known, are sold as ornaments, 
and some of the rarer kinds are greatly prized by collectors. A small yellow 
species, the money-cowry ( Cyprcea moneta), abundant in some parts of the Indian 
and Pacific Oceans, is used as coin in India and among the negroes of certain 
parts of Africa. The orange cowry ( C. aurora), one of the finest of the group, 
used to be worn by the chiefs in the Friendly Islands. The cowries, of which 
nearly two hundred species are known, are found most abundantly in tropical 
regions, but a few stragglers occur in temperate seas. Only one small and ridged 
species ( 0 . europcea) is found on the British coasts, and about a hundred fossil 
forms, chiefly Tertiary, are known. The genus Ovula is allied to Cyprcea as 
