54 



they should afterwards be put on gummed 

 paper. 



Order 15. DIPTERA. Wings two, naked, 

 unprotected ; halteres (poisers or balancers) 

 placed behind, and generally beneath the wings ; 

 head distinct from the thorax by an evident in- 

 terval; proboscis (rarely wanting) univalve ; 

 tar si , with two simple nails. [PI. Ill, fig. 7-] 



Tl>c Dipt era are easily distinguished from 

 the other orders of insects by having only two 

 wings. They are extremely numerous, and many 

 of the exotic species are very large. This 

 order contains the Tipuliada or Crane-flies, 

 Gnats, House-flies, the Bots of Cattle, &c. 

 The Diptcra of foreign climes are certainly less 

 known than any other order of insects ; those 

 persons, therefore, who may have the opportu- 

 nity, will render a most essential service to En- 

 tomology by collecting them: they feed, for the 

 raost part, on animal and vegetable juices, and 

 are generally quick on the wing ; they are found 

 in the blossoms of flowers in woods, meadows, 

 banks of rivers, and morasses ; during the day 

 they are on the wing, and may often be taken 

 while settling on flowers and the trunks of 

 trees, especially before rain ; when they may 



