TIPULIDJE. 29 



9. TIPULID^J. 



Large to moderately small, slender flies, with long, slender 

 legs. Head spherical, occiput strongly developed ; face often 

 produced snout-like. Eyes round, separated by the broad 

 front; sometimes approximated below the antennae; ocelli 

 usually wanting. Antennae rarely shorter, usually longer 

 than the head and thorax together; bead or thread-like, 

 composed of from six to nineteen joints ; the joints of 

 flagellum never plumose, but usually with more or less 

 conspicuous, bristly hairs ; the joints sometimes serrated. 

 Proboscis more or less projecting, in a few genera very much 

 elongated; palpi four or five jointed; the terminal joint often 

 elongated, whiplash-like. Thorax convex, usually with a very 

 distinct suture in the form of a shallow V ; pro-thorax usually 

 distinct, collar-like; scutellum half round; metanotum strong- 

 ly developed. Abdomen cylindrical, composed of seven or 

 eight segments ; genitalia prominent, in the male very varia- 

 ble in structure ; in the female the ovipositor with two pairs 

 of long, horny, pointed valves. Legs very long and slender ; 

 the tibiae sometimes with terminal spurs. Wings long, but 

 comparatively narrow ; in rest spread apart or lying par- 

 allel over the abdomen ; always six longitudinal veins ; usually 

 a complete discal cell ; both basal cells long ; the anal cell 

 usually open ; seventh vein distinct (save in the Ptychop- 

 terince) and of variable form ; alulets rounded, rarely angular. 



The family Tipulidae comprises the largest of the Nemato- 

 cerous flies, some of which exceed two inches in length. The 

 legs are very elongate and delicate, so delicate, indeed, that one 

 seldom succeeds in capturing the flies without the loss of one 

 or more. Flies of this description with a distinctly impressed 

 V-shaped suture on the dorsum of the thorax will be immedi- 

 ately recognized as belonging to this family. The female 

 differs from most other flies in having the ovipositor often 

 adapted for depositing eggs within the ground or other firm 

 substances. When the weather is favorable the eggs hatch 



