GALLERY.] NATURAL HISTORY. Ill 
larger, and have much more ventricose whorls to their 
shells than the males. The eggs of these animals are 
contained in coriaceous cases, each holding many eggs, 
of which only a few gradually enlarge and come to per¬ 
fection. The cases of Buccinum undatum , and Fusus 
despectus have been mistaken for the eggs of the oys¬ 
ter, and called oyster spat. This error is the more re¬ 
markable, as oysters are ovoviviparous, the young being 
found in the branchiae of the parent in the month of July: 
the eggs of Purpura and other genera have, by a similar 
error, been described as a species of Tubularia. 
The species of these shells are extremely apt to vary 
according to the roughness or smoothness of the sea they 
live in, and the quantity and quality of their food; thus, 
some of the common Whelks are thick and rugose, others 
very thin, even, and finely coloured. Rarely the whorls 
of these shells turn contrary to the common direction, 
from left to right, and sometimes, when the shell has been 
injured in its growth, the succeeding whorls are turned 
out of their usual course, and the shell becomes very 
much elongated or bent. (See p. 87> Cases 3 and 4.) 
The larger species are used as food by the natives of 
the sea-coast, and as bait by the fishermen. In Scotland 
the shell of the large Fusus despectus is used as a lamp. 
In India and China the different species of Turbinellus are 
used to contain the oil to anoint the priests. The animal of 
Purpura Lapillus yields a beautiful purple colour, Avhich 
has been considered as the Tyrian dye of the ancients ; but 
there is little doubt that this colour was obtained from 
various species, which were most common in the district; 
the true Tyrian dye was most probably derived from 
Mur ex trune ulus. 
The family of Strombidce (Case 1, 2) are peculiar for 
having a very compressed foot, which only allows them to 
leap and not to walk; their eyes are large, and placed on 
the end of a large thick elongated peduncle, having the 
slender tentacles arising out of the middle of the hinder 
sides, and the shell is peculiar for having a deep sinus 
placed on the side near the canal over the head of the ani¬ 
mal, when it is expanded. These animals, when they ar¬ 
rive at their full size, expand the edge of the mantle in a 
remarkable degree, which causes the shell of the adult ani- 
