ClASS V. INSECTA. 289 



iTialion. lie observed that the mouth contains the whole of the 

 usual parts which, under various modifications, exist in all insects : 

 the mandihics are perfectly distinct from ai:id unconnected with the 

 maxillu- : the maxilke are inserted behind, and somewhat below the 

 mandibles, whose base they conceal ; and the articulation of the 

 labrum is very evident from its semitransparency." Leach, Zuol. 

 Misc. vol. iii. 



Mr. Kirby, in the second volume of his Monographia Apum An- 

 gVuc, gives the following account of S/j/lops Mtlittu : " Upon this in- 

 sect {Mcliiiu iiigro-cenca) I discovered, last spring, a very singular 

 animal, which seems appropriated to the present genus. I had pre- 

 viously more than once observed upon other sp'^^^ies something that 

 I took to be a kind of Acarus, which appeared to be immovably fixed 

 just at the inosculations of the dorsal segments of the abdomen; at 

 length, finding three or four upon a specimen of MelUta nigio-cenea, 

 I determined not to lose that opportunity of t{U-;ing one off to ex- 

 amine and describe; but what was my astonishment when, upon 

 my attempting to disengage it with a pin, I drew forth from the 

 body of the McVttta a white lleshy larva, a quarter of an inch in 

 length, the head of which I had mistaken for an Acarus I After I 

 had examined one specimen, I attempted to extract a second ; and 

 the reader may imagine how greatly my astonishment was increased, 

 when, after I had drawn it out but a little way, I saw its skin burst, 

 and a head as black as ink, with large staring eyes and antennae, 

 consisting of two branches, break forth, and move itself briskly 

 from side to side. It looked like a little imp of darkness just emerg- 

 ing from the infernal regions. My eagerness to set free from its 

 confinement this extraordinary animal may be easily conjectured. 

 Indeed I was impatient to become better acquainted with so singular 

 a creature. When it was completely disengaged, and I had securctl 

 it from making its escape, I set myself to examine it as accurately 

 as possible ; and I found, after a careful inquiry, that I had not only 

 got a non-descript, but also an insect of a new genus, whose very 

 class seemed dubious." For hnlher information on this Order I 

 must refer the reader to the eleventh v(jlunie of the Transucilons of 

 the Lliniean Socid^, S(»rc?h/s Brifis/i I\lisccllaiii/, and Leach's Z'uolu- 

 gical Miscellany, vol. iii., all of which contain figures of the insects 

 of this Order. 



Order XV. DIPTERA. Lium, Leach, Latr., S)-c, 



Class A>Ti,iATA. Fair. 



The insects composing this Order are distinguished from all other 

 insects by the following characters. Wings two, naked, unprotected 

 llaltercs (poisers or balancers) placed behind, and generally beneath 



T 



