DIPTERA. 459 



The female deposits her eggs under the hide of healthy oxen and cows, of 

 not more than two or three years of age. The consequence of this operation 

 are tumours or lumps, on the internal pus of which the larvee feed. Horses 

 also are subject to them. 



The rein-deer, antelope, hare, &c., also nourish various larvae of (Estri, but 

 of a different species. 



(E. ovis, Lin. Five lines in length, and but slightly pilose ; head greyish ; 

 thorax cinereous, with elevated black points; abdomen yellowish, finely 

 spotted with brown or black; legs pale-brown ; wings transparent. The larva 

 inhabits the frontal sinus of the sheep. That of the species called trompe, 

 Fab., is found in the same parts in the rein-deer. 



(E. equi, Lat, Clarck. But slightly pilose, and of a fulvous brown ; abdo- 

 men paler ; two points and a band on the wings, black. The female deposits 

 her ova on the legs and shoulders of horses ; the larvae inhabit their stomach. 



The third tribe of the Athericera, that of the CONOPSARI.E, is the only one 

 of that family in which the proboscis is either always salient and siphoniform, 

 cylindrical or conical, or setaceous. The reticulation of the wings is the same 

 as in our first division of the Muscides. 



Most of these insects are found on plants. They form the genus 



CONOPS, Linnceus. 



In Conops properly so called, the two last joints of the antennae form a 

 club, with a terminal stilet. 



C. rufipes, Fab. Black ; abdominal annuli edged with white ; base of the 

 abdomen and legs fulvous ; edges of the wings black. 



It undergoes its metamorphosis in the abdomen of a living Bombus, and 

 issues from between its rings. 



Our fourth and last tribe, that of the MUSCIDES, is distinguished from the 

 three preceding ones by a very apparent, always membranous and bilabiate 

 proboscis, usually bearing two palpi (the Phorae alone excepted), susceptible 

 of being entirely retracted within the oral cavity ; and by a sucker composed 

 of two pieces. The antennae always terminate en palette with a lateral seta. 



This tribe will comprise the genus 



Muse A, Linnceus, 



Or that of the flies. Antenna? inserted near the front, palpi placed on the 

 proboscis, and retiring with it into the oval cavity, and transverse nervures in 

 the wings, characterise a first section of the Muscides, which will include 

 eight principal groups or sub-tribes. 



These groups are composed of various subgenera we will merely particu- 

 larise that of 



Musca, properly so called, or the true Fly, where the abdomen is triangular, 

 and the eyes are contiguous posteriorly, or closely approximated in the males. 



Here come most of those flies whose larvae feed on carrion, meat, &c. ; 

 others of the same subgenus inhabit dung. They all resemble soft whitish 



