352 MOSTLY MAMMALS 
the islanders of Eastern Asia for personal adornment, for 
weighting their fishing nets, and as a means of exchange; 
while in the latter respect the well-known money cowry has 
a still more extensive use over a large part of Asia. 
But it is from the peculiarities of their structure and 
coloration that these beautiful shells claim our attention in 
the present article. Taking any common species, it will be 
seen that the upper surface of the shell approaches more 
or less to an egg-shape, with a notch at each extremity 
forming the terminations of the mouth below. Somewhat 
to the right of the middle line in most species runs a 
straight or slightly sinuous line over which the pattern of 
the rest of the upper surface does not extend, this line 
marking in the living animal the limits of the right and 
left lobes of the so-called mantle, which during activity 
extends upwards from the foot on which the creature 
crawls to develop the rest of the shell. Compared with 
an olive, in which the spire is relatively small, the shell of 
an adult cowry differs by the rudimentary condition or 
even absence of a spire; while on the under-surface the 
narrow mouth of the shell (not, be it understood, of the 
animal) is remarkable for the series of vertical ridges, or 
“teeth,” with which its edges are armed. 
Now, since almost all other univalve shells related, even 
remotely, to the cowries, have a more or less elongated 
spire at the hinder or upper end, the inquirer naturally 
seeks to find out the reason for the disappearance of this 
part in the members of the present group. In a fully 
adult specimen of the common black-spotted tiger cowry 
no trace at all of the spire can be detected, but in the 
equally common Surinam-toad cowry a more or less distinct 
remnant, partly buried in the abundant cement, is observable 
even in the adult. In Scott’s cowry the spire is much 
