166 PECTINIBRANCHIATA.—CYPREADZ. 
chiffonier, my readers will be at no loss for the 
means of actual comparison of the following cha- 
racters by which it is distinguished. he shell is 
oval, more or less swollen, and flattened on the 
inferior side: its surface is polished or enamelled, 
commonly smooth, but sometimes marked with 
parallel grooves: the aperture is as long as the 
whole shell, narrow, forming a canal at each extre- 
mity ; the outer lip is in full age bent inward, and 
much thickened, and as well as the inner lip, (or 
that edge of the aperture which faces it,) in almost 
all the species marked with numerous parallel 
tooth-like ridges. 
The animal has large smooth, or warted mantle- 
lobes, capable of entirely embracing the shell 
between them, their edges meeting along its sum- 
mit. The head is broad, with a retractile pro- 
boscis, and long, pointed tentacles, at the bases of 
which are the prominences which carry the eyes. 
The jaws are horny, and there is a long nibbon- 
like tongue, armed with rows of minute-teeth. 
Some species appear to have the faculty of 
changing the colours with which the mantle is 
vividly adorned. Mr. Stutchbury, who had an 
opportunity of examining many individuals of 
C. tigris at the Pearl Islands, has stated that those 
cowries lived there in very shallow water, and 
always under rolled masses of madrepore. They 
never were to be seen exposed to the sun’s rays. 
On lifting one of those masses a tiger-cowry was 
generally observed with its shell entirely covered 
by the large mantle, which was mottled with dark 
colours, the intensity of which the animal seemed 
to have the power of changing; for the colours 
varied in the same light and in the same medium, 
