THORAX. 



33 



Notopleiiral or dorsopleural suture, the suture running 

 from the humerus to the root of the wings, separating 

 the mesonotum from the pleura. 



Stcrnopleural suture, the suture below the dorsopleural 

 suture, nearly parallel with it and separating the meso- 

 pleura from the sternopleura. 



Mesopleural suture, the suture running from the root of 

 the wings downward and separating the mesopleura from 

 the pteropleura. 



Mesopleura, the space situated in front of the root of the 

 \vings, between the dorsopleural and sternopleural su- 

 tures. 



Pteropleura, situated below the root of the wings, back 

 of the mesopleural suture. 



Sternopleura, the lower part of the pleura, below the 

 sternopleural suture and above the front coxa. 



Hypoplcura, the space over the middle and hind coxae, 

 below the metapleura. 



Metapleura, the 'sides of the metanotum', a more or 

 less swollen space at the outside of the metanotum and 

 between it and the pteropleura and hypopleura. 



Metanotum, the oval, arched portion below or behind 

 the scutellum. It is frequently most easily observable in 

 flies with a long, slender abdomen, as the Tipulidae. 



Halteres, balancers or poisers, rudimentary posterior 

 wings, a slender organ with a dilated head, situated be- 

 low each metapleura. 



SquamcE, Tegulce or Calyptrce, a pair of membranous 

 scales situated above the halteres and back of the root of 

 the wings, one above the other. The lower one or both 

 may be rudimentary or absent ; the upper one moves \vith 

 the wings and is called the antitegula by Osten Sacken. 

 Comstock, however, objects to this use of tegula, saying 

 that the term was first used for the cup-like scale above 

 the root of the wing in certain hymenoptera, and should 

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