ZOOLOGY. 



1. Oestrus, Gad-Fly. AnienncB three jointed, the middlq 

 one globular, short, deeply seated ; fig. 37, plate 3 ; 

 face broad, depressed ; mouth a simple aperture not 

 projecting* feelers two, sunk two-jointed; tail 

 inflected. 



This genus is exceedingly troublesome to horses, cattle, 

 and sheep, in the skins of which they deposit their eggs ; 

 which soon change into larvae, that feed under the skin of 

 living animals ; the larvae are soft, smooth, annulate, with- 

 out feet, and in most species furnished with hook-like apen- 

 dages. 



2. Tipula. Cuane-Fly. Mouth arched over, by the upper 



jaw extending from the head ; antennce filiform, short ; 

 feelers two, recurved, filiform, longer than the head ; 

 mouth furnished with a very short recurved proboscis. 



Many species of this genus resemble Gnats, they feed on 

 various substances ; larvae without feet, soft and cylindrical ; 

 pupa cylindrical, horned ; some species reside amongst the 

 roots of aquatic vegetables, others, among grass ; but by far 

 the greater number are aquatic. The perfect flies are found 

 in abundance in the autumnal months. 



3. Diopsis. Antennw very small, setaceous ; eijes placed 



on very long foot- stalks. 



£). Musca. Fly. Antennce very short ; palpi wanting; 

 mouth furnished with a soft ^ebhy proboscis^ with two 

 equal lateral lips. 



