378 THE PUPIPARA. 



tongue of the animal, and can easily pass down into 

 his intestines. The larva is well supplied with rings 

 of short bristles, to enable it to retain its position in 

 the intestines of its host, and also with a pair of 

 strong hooks upon the head, which probably assist in 

 the same operation. 



Suborder Pupipara. 



This, the last suborder of the Diptera, is not only 

 distinguished from the rest of the order by its remark- 

 able mode of reproduction, but also by the peculiar 

 •structure of its mouth, the parts of which this is com- 

 posed being so unlike anything that occurs in other 

 groups of Diptera, that no entomologist has yet suc- 

 ceeded in satisfactorily determining their nature. On 

 examining the lower part of the front of the head of 

 one of these insects, a pair of minute palpiform organs 

 is seen, and beneath these a small orifice, through 

 v/hich a slender bristle-like organ can be protruded. 

 This, however, consists of three bristles, generally 

 described as the representatives of the labrum, labium 

 and tongue, which are supported upon a muscular 

 base, by the action of which the compound organ 

 can be exserted or retracted at the will of the animal. 

 The antennae, which are very small and somewhat 

 resemble those of the preceding suborder in structure, 

 are concealed in small pits in the neighbourhood of 

 the eyes. The head is closely applied to the thorax, 

 which is depressed, and has a very broad sternum, so 

 that the legs are situated wide apart towards the 

 sides of the body. The tarsi are terminated by two or 

 three large claws, fitted to enable the insects to take 



