368 



THE ANATOMY OF INVERTEBRATED 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 line 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 maxillae ; and that there are no mandibles. 



Fig. 108.— SyrphKs rlbesii.—K. Larva. B. Pupa. C. Ima^o. (" Regne Animal.'") 



The ordinary Z^^/^^era, which possess one pair of functional 

 wings attached to the mesothorax, resemble the Ifemiptera 





Fig. 109.— Erisf alls floreus.—d, front of the head; e. labrum; /. mandible : (/. maxilla 

 and palpus ; i, iabiam ; ?!*. extremity of the labium separately mid more matrni- 

 fied ; **i, inner surface of the paraglo^sse ; ***/. the rows of hairs on the inner 

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



in possessing a usually fleshy proboscis, often tumid at its 

 extremity, which is formed by the confluent second maxillae. 



