COIWRIES, 511 
time the lobes of the mantle expand over it on either side, and by degrees 
deposit so thick a layer of smooth, shining substance, that the spire is 
entirely hidden. The pale streak which generally exists along the back of 
the Cowries indicates the line where the edges of the mantle nearly meet. 
This little Cowry is so well known as to need no description. 
The celebrated MONEY CowrRY (Cyfr@a moneta) belongs to this genus. 
These little white shells are well known as being the medium 
of barter in many parts of Western Africa; and vast 
multitudes are gathered from their home in the Pacific and 
Eastern seas, and imported intu this country for the purpose 
of immediate exportation to the African coast. Sixty 
tons’ weight of Money Cowries have been freighted at a single 
British port in one year. MONE COWR Ye 
The grooved or wrinkled edges of the lip are well known (Aric a mone a) 
to everyone who has handled a Cowry, and these ridges 
assume a remarkable development in the DEEP-TOOTHED Cowry. a figure 
of which is here given, the empty shell being laid so as to exhibit the opening 
and the lips. The colour of this shell is extremely variable, but is mostly a 
mottled wood-brown, sometimes diversified with bands, and dark inside. It 
is not a very large species. 
WE now arrive at a vast army of shells called the SEA SNAILS, and 
distinguished by having the edges of the aperture without notches, the 
shell spiral or limpet-shaped, and the operculum either horny or covered with 
hard, smooth, shelly matter. 
One of the most curious of these shells is the SPINED NERITINA. The 
operculum is shelly, with a flexible border, and has some small teeth on its 
strait edge. All the Neritinze are globular in their general shape, darkly 
DEEP-TOUTHED COWRY.—(Cyr@a caurica.) SPINED NERITINA.—(WVeritina spinosa), 
spotted or banded with black and purple, and covered with a polished bone- 
like epidermis. The colour of the Spined Neritina is deep green black on 
the exterior and blackish white within. The sheli is thick and solid at the 
aperture, but becomes thinner towards the interior. 
IN the tamily of the Turritellidze, the shell is either tubular or spiral ; the 
aperture is not waved, notched, or formed into canals ; the foot is very small, 
the muzzle is short, and the eyes sunk rather deeply into the base of the 
tentacles. 
THE lower figure in the accompanying engraving represents thé empty shell 
of the STAIR-CASE or PRECIOUS WENTLETRAP, in former days cne of the 
scercest and most costly of the specimens of which a conchologist’s cabinet 
