364 TIPULIDJE. 



backwards ; scape with the 2nd joint usually, sometimes con- 

 siderably, enlarged ; flagellar joints subglobular, elliptical or short 

 subcylindrical, pubescent, the longer verticels of hairs differing 

 considerably in length according to the species, being sometimes 

 quite inconspicuous. Thorax normal, the anterior part prolonged 

 into a distinct though not conspicuous neck, the side view of the 

 prothorax triangular or subtriangular. Abdomen normal, of 

 moderate size, linear, usually with parallel sides and soft short 

 pubescence, which is often very inconspicuous or apparently 

 confined chiefly to the sides and posterior borders of the segments ; 

 the segments in some species very distinct, in others much less so. 

 Genitalia of male consisting of a pair of movable fleshy lobes, 

 oblong, often subreniform, each armed on the inside with a short 

 curved horny appendage, something like a beak, called by Osten 

 Sacken a " rostriform " appendage, and often bearing on its convex 

 side one or two stiff bristles. To the upperside of each of the 

 lobes, another horny appendage, long, slender, attenuated, curved, 

 is closely applied, and to these organs Osten Sacken gives the 

 name of " falciform " appendages, their point of attachment being 

 the horny, posteriorly pointed, basal plate below. Most of the 

 different parts of the male organ appear liable to considerable 

 modification in different species. In the female, the ovipositor 

 is generally noticeable by its comparatively small size. The upper 

 valves are short, narrow, arcuate, pointed, the lower ones straight. 

 Leys generally slender, in some species, especially those of larger 

 size, less so ; usually more slender and often much longer than in 

 Limnobia ; the pubescence very incouspicuous, often microscopic. 

 " Most of the species have a distinct tooth on the underside of 

 the ungues, near the base, sometimes followed by a smaller one " 

 (Osten Sacken). Wings somewhat elongate. Venation, though 

 typical, showing considerable modifications within certain limits.* 

 One subniarginal and four posterior cells ; discal cell generally 

 closed. Auxiliary vein ending in costa opposite, or at a little 

 beyond base of, 2nd longitudinal vein, that is to say, never very 

 much before or beyond the middle of the wing ; in occasional 

 species it ends a little before the origin of the 2nd vein, and in 

 quite exceptional cases considerably beyond this point. Subcostal 

 cross-vein placed in different species at different distances from 

 the tip of the auxiliary vein, its position, however, being constant 

 in the same species. The 1st longitudinal vein ends in the costa 

 near the end of the nearly always present stigma, more or less 

 beyond the inner end of the submarginal cell, sometimes ending 

 as far distally as the middle of this cell, t The marginal cross- 

 vein placed near tip of 1st vein, often more or less in a Hue with 

 the upturned end of the latter, but also often quite distinctly 

 appearing as a true cross-vein, a little anterior to the tip of the 



* Especially when the species of the whole world are considered, 

 t Vide notes ou venation, post. 



