197 



— Apical abdoiuiual voiilral se:;ni('iit with hlood-^ills in llic form of 



an irrcf^iilar j)rotuberan('e, rarely acute laterally 9 



2. Ventral blood-gills not cons{)icuously longer than the stellate proc- 



esses on margin of stigniatal field, these processes slender, regu- 

 larly and very conspicuously fringed Tipula sp. 1. 



— Ventral blood-gills conspicuously longer than stellate i)i'occsses, or 



the latter not regularly and conspicuously fringed, or the proc- 

 esses very unequal in length 3 



3. Stellate processes subequal in length, very short, their margins with 



regular fringe of short hairs 5 



— Stellate processes very unequal in length, the ui)per two short, the 



lateral and lower ones much longer and with isolated groups of 

 long hairs 4 



4. Very large species, more than 40 mm. in length ; penultimate abdom- 



inal segment with a lateral process Tipula sp. 2. 



— Small species, 20 mm. in length ; penultimate abdominal segment 



without a lateral process Tipula sp. 2a. 



5. Small species, not more than 30 nun. in length 6 



— Larger species, more than 40 mm. in length 7 



6. Body with dense pubescence which is most conspicuous on 2 narrow 



longitudinal lines on dorsum, giving the species the appearance 

 of being vittate ; posterior latero-ventral bristles surrounded with 

 stiff upright hairs Tipula eluta. 



— Body without dense pubescent vittae; posterior latero-ventral 



bristles not surrounded with stiff upright hairs . Tipula cunctans. 



7. Body almost regularly cylindrical, as in eluta; posterior latero-ven- 



tral bristles not on pseudopod-like elevations, their bases sur- 

 rounded with short, stiff, upright hairs; dorsum not conspicuously 

 vittate Tipula sp. 4. 



— Body not regularly cylindrical, the segmentation deep, and the pos- 



terior segments with distinct pseudopod-like elevations ; poste- 

 rior latero-ventral bristles situated on elevations and not sur- 

 rounded with stiff upright hairs ; dorsum conspicuously vittate 

 8 



8. The pale dorsal vittae composed of a number of closely placed pale 



dots ; dorsum with many small pale paired spots ; hairs not in- 

 serted in dark brown dots Tipula ahdominalis. 



— The pale dorsal vittae linear ; dorsum with a number of very incon- 



spicuous pale dots ; hairs inserted in dark brown dots. Tipula sp. 3. 



9. Apical abdominal segment with a conical protuberance on each side 



proximad of the processes on the margin of stigmatal field (PI. 



XXXI, Figs. 6, 7) Tipula sp. 6. 



- — Apical abdominal segment without a protuberance on sides 10 



10. Upper 4 processes on anal segment deeurved, long, and pointed, much 

 longer than lower pair, ventral respiratory organs acute laterally 

 (PI. XXXII, Figs. 7, 8) ; prothorax with 2 horny protuberances 

 on its dorsal margin anteriorly Tipula sp. 5. 



