510 



THE INVERTEBRATA 



consists of small flies with a hump-backed appearance and with broad 

 wings. The spindle-shaped larvae live in running water and are cha- 

 racterized by the possession of prothoracic prolegs and an anal pad 

 provided with setae by means of which they cling to rocks etc. in the 



Fig. 350. Types of Diptera. Tipula ochracea (Tipulidae). B, Chrysops 

 caecutiens (Tabanidae). C, Contarinia nasturtii (Cecidomyidae). D, Hypo- 

 derma bovis (Cyclorrhapha, Oestridae). C, from Smith after Taylor ; D, from 

 Smith after Theobald. 



rapidly flowing water of their environment. Still included in the 

 suborder Orthorrhapha are the flies with short antennae, the Brachy- 

 cera. Though included in this scheme with the Orthorrhapha their 

 venational characters indicate a close relation with the Cyclorrhapha. 

 In general, the basal joints of the antennae are larger than the terminal 



