GLOSSARY OF TERMS USED IN DIPTl^ROLOGY 483 



COMSTOCK-NEEDHAM SYSTEM OF WING VENATION. 



The comparison of the system here used is with that of Comstock-Needham. 

 not as revised by Tillyard and others. 



Anal cell — Cu. 



Anal crossvein — Cu^.. 



Crossveins — h;r-m; m; M3; Cu-; Sc^. 



Discal cell — 1st M?. 



Discoidal crossvein — Ms. 



Fifth longitudinal — Cu 1, 2. 



First basal cell — R. 



First vein — R plus Ri. (the main stem of the vein, basad of Rs, is R, — beyond 



Rs, R,). 

 Large crossvein — m and outer section of M3. 

 Marginal cell — Ri. 

 Posterior cells — R:. to Cu,. 



Posterior crossvein — m, and sometimes also outer section of M3. 

 Prsefurca — Rs. 



Second vein — Rs, and its anterior branch, Rj*3. 

 Small crossvein — r-m. 

 Subcostal crossvein — Sd.. 

 Submarginal cells — R3, R4. 



Third long, vein — Posterior branch of Rs, — R4+5. 

 Compressed — Flattened from side to side — laterally compressed. 

 Connate — Fused and immovable. 

 Constricted — Narrowed. 



Corneous — Horn-like in texture or appearing so. 

 Costa — See costal vein. 



Costal cell — The cell between the costa and subcostal or auxiliary vein. 

 Costal vein — The vein extending along the front margin of the wing. 

 Crossveins — There are five typical crossveins in the wings: humeral, anterior, 

 posterior, discoidal and anal (The equivalents of these in the Comstock- 

 Needham system are, in order, — h; r-m; m; M3 and Cu.). In addition 

 to these there is the subcostal crossvein (Scj), and there may be one or 

 more veins simulating crossveins. The apical crossvein is merely the 

 anteriorly curved fourth longitudinal vein (Muscoids). The base of the 

 third vein, base of posterior branch of the fourth vein and the base of the 

 branches of the fifth vein may simulate crossveins. In some families 

 there may be additional crossveins (see Nemestrinidae, Bombyliidse, etc.). 

 Cruciate — Crossing each other. 

 Ctenidium — A comb-like row of bristles. 

 Cubitus — Fifth longitudinal vein. 

 Decumbent — Depressed; hanging down. 

 Decussate — Crossing or cruciate. 



Depressed — Flattened dorsoventrally, contrasting with compressed. 

 Dichoptic — Eyes separated by the front. 

 Digitate — Bearing a finger-like process. 



Discal cell — A (usually) closed cell (on the disc of the wing, lying between the 



fourth and fifth veins). It may be absent, open apically, or united with 



one of the basal cells, usually the second basal, abnormally with the first 



basal (1st M^). 



Discal crossvein — The vein separating the discal and second basal cells. (See 



discoidal crossvein.) (M3 of Comstock-Needham system). 

 Discal scutellars — Bristles on the disc of the scutellum. 

 Discoidal crossvein — The vein separating the discal and second basal cells. 



(See discal crossvein.) (Ms of Comstock-Needham system). 

 Dorsad — Toward the upper surface. 



