32 SCIENCE SKETCHES. 
mouth; its body was exceedingly slim and round, 
as transparent as jelly, but hard and firm to the 
touch. Its belly and much of its back were quite 
bare of scales, and those along its sides were small 
and inconspicuous. After much searching through 
the scattered descriptions which Eastern naturalists 
have given us of the darters found in their bottles 
of alcohol, we decided that our little friend was the 
Pellucid Darter (Ammocrypta pellucida Baird), 
better called the “Sand Darter” for reasons soon 
to be given. 
Our aquarium had been arranged for the con- 
venience of our other Etheostomine friends, and 
the bottom was thickly covered with stones among 
which a small fish might easily hide. Several days 
passed after the introduction of the first Amzo0- 
crypta! which survived the change of water, when 
we noticed that it had disappeared. Careful search 
among the stones and around the geode only made 
it the more certain that it had gone, and increased 
our wonder as to the way; for surely it had not 
been eaten, nor had it jumped out, unless, like 
Ariel, it could assume a “shape invisible.” Finally, 
after going over every inch of the ground, there 
was discovered, under the nose of Boleosoma, 
which was standing as usual on its hands and tail, 
the upper edge of a caudal fin, and on each side 
of Boly’s tail appeared a little black eye set in a 
yellow frame. Pleurolepis was buried! Was he 
dead? Slowly one eye was closed in a darter’s 
inimitable way, — for they can outwink all animals 
} Or, as we then called it, Plewrolepis ; this name being earlier, 
but already preoccupied by a genus of extinct ganoid fishes. 
