88 The Sand Darter. [ February, 
know has a tip nearly as hard as horn, against the bottom, stood 
nearly straight on its head, and with a swift beating of its tail 
to the right and left was in less than five seconds completely 
buried. The sand had been violently stirred, of course, and just 
as it had nearly settled, probably in less than half a minute, its 
nose was pushed quietly out and, settling back, left the twinkling 
eyes and narrow forehead alone visible. $ 
Since then we have kept scores of them in an aquarium ar- 
ranged especially for their convenience, and have often seen them 
burrow into the sand. They will remain buried as long as the 
water is pure and cool, and indeed we now rely nearly altogether 
upon them to warn us when the water needs changing. They 
then come out and lie on the bottom, panting violently. We 
have been unable to discover any immediate incentive for the 
act. It seems to be entirely unpremeditated. A number of 
them in confinement lie helplessly on the bottom, motionless 
and slowly breathing, when one suddenly starts and buries its 
head and neck in the now whirling sand by a motion as quick as 
thought, a headless tail beats frantically about, and when the 
clean sand lies smoothly on the bottom again the little eyes are 
looking at you like two glistening beads, as if to witness your 
applause at so clever a trick.} 
We never have seen a Pleurolepis taste of food, nor do we 
expect to, for although its mouth bristles with teeth its small 
size forbids an attack on any game which we can offer. Its 
quiescent habits, and the character of the bottoms to which it 
confines itself, seem to indicate that its prey is minute if not 
microscopic. But speculation about what we don’t know as to 
its food might lead us to speculation as to the mode of evolution 
of its characteristic features; how, for instance, the hard snout 
and the burrowing habits are consequent upon the loss of scales, 
or how the loss of unnecessary scales are consequent on its bur- 
rowing habits, matters not within the defined scope of this article. 
Specimens of this species may be readily obtained in regions 
where it occurs. We have taken at one drawing of a fine-meshed 
minnow net, no less than twenty-four individuals over a sand- 
bar in White River, above Indianapolis, where the usual depth 
of the water is about two feet. 
1 Since this article was written, a small Boleosoma (B. brevipinne no in Pro- 
fessor Copeland’s aquarium has been noticed to bury himself in the sa as persist- 
ently as the Pleurolepis does, and in similar fashion, In no other earal of this 
species, and in no other species excepting the “ Sand Darter,” have we noticed this 
habit, although during the last two years we have had hundreds of individuals under 
examination, — D. S. J. 
