UNIVALVE MOLLUSCA. 453 
with flexual lines of a yellowish brown, with two brown bands, 
combined with the fine yellowish tint of gold colour within. Oliva 
porphyria, from the Brazil coast (Fig. 276), presents lines of a reddish 
brown, regularly interlaced with spotted large brown marks, upon a 
flesh-coloured ground. Odiva irisans (Fig. 277) is painted in zigzag 
lines, close and brown, edged with orange-yellow, and with two zones 
of darker brown, and reticulated. Ova Peruviana (Fig. 278) is 
farrowed with regularly spaced bands. 
In the genus Cassis the shell is oval, convex, and the spire is 
Fig. 275. Fig. 276. Fig. 277. Fig. 278. 
Oliva erythrostoma Oliva porphyria Oliva irisans Oliva Peruviana 
(Lamarck). (Linnaeus). (Lamarck). (Lamarck). 
not of considerable height. The longitudinal opening is narrow, 
terminating in front in a short channel, which becomes suddenly 
erect towards the back of the shell, as in Cassis glauca (Fig. 279), a 
fine shell from the Moluccas. The columella is folded or toothed 
transversely, as in Cassis rufa, Fig. 280; the right edge thick, 
furnished with a sort of pad externally, and dentate within. This 
shell is from the Indian Ocean, and is of a fine purple colour, varied 
with black above; the edges of the opening being of a coral red 
colour, the teeth alone being white. 
The head of the animal is large and thick, furnished with two 
conical elongated tentacles, at the base of which are the eyes. The 
mantle is ranged outside the shell, falling back upon the edges of the 
opening, and terminating at its anterior extremity in a long cylindrical 
channel, cloven in front, and passing by a hollow at the base into the 
