THE SEA SNAILS. 



599 



This little Cowry is so well known as to need no description. 

 The celebrated Money Cowry ( Cyprcea monetd) belongs to this genus. 

 These little w^iite shells are well known as being the medium of barter 

 in many parts of Western Africa, and vast multitudes are gathered 

 from their homes in the Pacific and Eastern seas, and 

 imported into this country for the purpose of imme- 

 diate exportation to the African coast. Sixty tons 

 weight of Money Cowries has been freighted at a 

 single British port in one year. 



The grooved or wrinkled edges of the lip are well 

 known to every one who has handled a Cowry, and 

 these ridges assume a remarkable development in the 

 Deep-toothed Cowry. The color 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 The Admiral 

 limpet-shaped, and the operculum either horny or ^^fy^rcdk) "^ 

 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 straight edge. All the Neritinse are globular in their general 

 shape, darkly spotted or banded with black and purple, and covered 

 with a polished bone-like epidermis. The color of the Spined Neritina 

 IS deep green-black on the exterior and blackish white within. The 

 shell is thick and solid at the aperture, but becomes thinner toward 

 the interior. 



In the family of the Turritellidse 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 Staircase or Precious Wen- 

 TLETRAP was iu former days one of 

 the scarcest and most costly of the 

 specimens of which a conchologist's 

 cabinet could boast. There was hard- 

 ly any sum which a wealthy connois- 

 seur — or virtuoso, as the fashion was 

 then to call those who were fond of natural history — would not give 

 for an especially large and perfect example of this really pretty shell. 



The Money Cowry {Cyprcea 

 moneta). 



