LiPURA fimetaria: its appearance and habits. 209 



not be detected so long as a pump was used unless the water had been 

 reduced to the level of the bottom of the pipe. A bucket dipping 

 from the surface would at once bring them to notice. 



Occurrence in a Well. 



Another communication contained the following statement: 



I inclose to you by mail in a bottle, four or five small insects which 

 are drawn up in the bucket of my well quite frequently. Can you inform 

 me what they are, and in what way they can be most easily exterminated.'' 

 The well is dug in a sandy clay, and is made of two and a half foot 

 cement pipe, the joints being cemented, and I fully supposed it was 

 worm, insect and vermin proof. At times hundreds are drawn up in a 

 day. They seem to live only on the surface of the water. 



As to their occurrence in the well, it was suggested in reply, that if 

 the well was an open one, the insects would originally have been at- 

 tracted by the cool, damp sides of its walls, and thence easily have found 

 their way to the water. It was no doubt somewhat disagreeable to see 

 living forms in association with water which we drink, but beyond this, 

 the presence of the PoduridiE in the well was not objectionable. As in 

 the case of those occurring in cisterns, they would undoubtedly serve 

 an excellent purpose in feeding upon and removing many of the impu- 

 rities that, without them, would accumulate upon the surface, to the det- 

 riment of the healthfulness of the water. In the event, however, of 

 their becoming annoyingly abundant, it was thought that they could be 

 diminished by dropping a moderate quantity of finely powdered lime 

 into the well. 



Its Appearance and Habits. 



We find among our writers no detailed description of this species, nor 

 good figure, and we therefore copy a rather crude one from Murray's 

 Economic Entomology, to aid in its identification. Fig. 65 

 gives a dorsal view of the insect. Although contained in the 

 I Tribe Collembola, which consists largely of the " spring-tails," 

 this species is without the jumping apparatus of the one pre- 

 viously noticed. Dr. Packard, in his Synopsis of the Thysa- 

 niira of Essex Co., Mass., places it in the subfamily of Lipii- 

 puRA FiMETA- vince, and characterizes it briefly as being white, naked, 



RIA (Linn.), ' J o i i 



diam?ters*'(Af" ^^'^^'^ a few Scattered hairs, and of the length of 0.06 of an inch, 

 ter Murray), j^. -^ ^^<^Yv^^ h\\xx\t at the tip, and is without the hooks at the 

 end of the abdomen that occur in an associate species, Lipura ambu- 

 lans (Linn.). 



27 



