66 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 1 39 



stock-Needham system. Mosquito taxonomists, however, usually 

 designate the veins behind the subcosta by numbers. In this scheme 

 R t is vein i, R% and R 3 are branches of vein 2, R i+5 is vein 3, M and 

 its two branches are vein 4, Cu and its two branches are vein 5, and A 

 is vein 6. The veins are densely clothed on both sides of the wing with 

 long, slender, fusiform, or scalelike setae (omitted in the figure). 



While the simple venation of the mosquito wing is of a fairly 

 generalized pattern, the basal wing structure has little resemblance 



R. S 



-'g G A Cu 2 Cuj M 3 2V2 

 --R 



-M 



--Cu 

 -A 



Fig. 26. — The wing and halter. 



A, Culex, left wing and halter, wing partly flexed on basal lobe, scales re- 

 moved to show venation. B, Anopheles, base of wing, flattened. C, Culex, halter 

 enlarged, posterior. 



A, anal vein ; C, costa ; Cu, cubitus ; M, media ; R, radius ; Sc, subcosta. 



to that of most other insects, and would appear to be specialized by 

 elimination of the usual axillary sclerites. When the wing is flexed 

 (fig. 26 A) a fold near the base sets off a triangular basal lobe by 

 which the wing is attached to the thorax. During flexion the wing 

 turns posteriorly over the basal lobe, which is then covered from above 

 by the fully flexed wing, and gives the wing the appearance of being 

 supported on a lobe of the thorax. The principal sclerotization of the 

 wing base is a long, anterior jointed bar (B, r) that supports the 

 radial vein, and bends at the joint when the wing is flexed (A). 



