368 



THE ANATOMY OF INYERTEBRATED ANIMALS. 



mals, birds, and bees, a circular wall, or short proboscis, in- 

 vests the other parts of the mouth. There are, first, two 

 lateral, protrusible, horny plates ; secondly, an anterior and a 

 posterior seta ; the latter stronger, and grooved longitudinally 

 in front. Between these is a single tine seta. Gerstfeldt 

 considers that the last answers to the hypopharynx ; the 

 second pair, to the labrum and the second maxillae ; the first 

 pair, to the first maxillo3 ; and that there are no mandibles. 



Fig. 103.—S]/rphus ribesii.—K. Larva. B. Pupa. C. Imago. (" Regne Animal.") 



The ordinnTy Dlptera, which possess one pair of functional 

 wings attached to the mesothorax, resemble the JSemiptera 



Pig. i09.—EnstcUisfloreus.—rl, front of the head; e, labrum; /", mandible ; ff. maxilla 

 and palpus ; z, labium ; ?:*, c-xtremity of the labiurn separately and more masiii- 

 fied ; **i, inner surface of the para?lo«sse ; ***i. the rows of hairs on the inner 

 surface ; I, the ligula ; m, the cardo and submentura. (After Newport.) 



in possessing a usually fleshy proboscis, often tumid at its 

 extremity, which is formed by the confluent second maxillae. 



