ON CREEPERS. 107 



fish, but they instinctively keep themselves close under 

 the stones. 



CREEPERS OF THE DRAKE CLASS. 



No eggs have been seen attached to the bodies of the 

 females of this class, but from their frequent dropping 

 upon the waters it may be supposed they then deposit 

 the germ of their creepers, which have an uncouthly 

 appearance when compared with their neat trim flies. 

 The heads of most of them are large and round, par- 

 ticularly those species which produce flies with large 

 gogling and case eyes ; thejr shoulders are round and 

 made larger by the enclosed wings ; the body and 

 whisks are similar to those of the flies, but more bulky, 

 and the whisks, legs, and some of the joints of the 

 body, set with fine hair, which flows and moves in the 

 water, and may answer the purpose of fins. The 

 smaller species require looking at closely to distinguish 

 them. They are of a jelly-like transparency ; the co- 

 lors and marks of the fly appearing through their thin 

 creeper skins ; they are much quicker in the water 

 than the flies are upon land, up to the last moment 

 before hatching. Some species may fix themselves to 

 something, but it is certain that the greater part, if not 

 the whole, class, hatch themselves on the top of the 

 water, and spring on the wing from the empty creeper 

 case as it floats on the current. 



4TH. GREEN DRAKE CREEPER. Length, about 

 three-quarters. Two short feelers, two or three whisks, 



