68 PLATE XXXL 



of a mofr. lingular ftructure. This happens about the latter end of 

 May^ or beginning of June^ if the weather proves favourable ; they 

 will then be found in (hallow Handing waters, crawling on the grafs or 

 plants which grow there, or they may be taken floating on the furface 

 of the water. The Body confifts of twelve annular divifions, whereof 

 the Head and Tail are two ; the Tail has a verge of hairs, which, 

 when entirely expanded, fupport the creature on the furface, with its 

 head downwards. If it whiles to defcend, it contracts the hairs in the 

 form of a wine glafs, or entirely clofes them at the end ; and when 

 again it is riling to the furface, it forces a bubble from a fmall aperture 

 in the center, which immediately makes a pafTage for its afcenfion. — 

 It changes to the Pupa flate, and about the middle of July to the Fly. 

 It fubfifts at this time on the nectar and other juices it extracts from 

 the bottom of the corolla in flowers. 



F I G; 



