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 Ammo- 

 crypta 1 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 



1 Or, as we then called it, Pleurolepis ; this name being earlier, 

 but already preoccupied by a genus of extinct ganoid fishes. 



