Crane-flies 



23 c 



destitute of pubesence; each of the outer setigerous areas bears two closely 

 approximated setae. Lateral setae two, one on each primary ring at about mid- 

 length, the anterior one lying closer to the ventral margin, the posterior one 

 closer to the dorsal margin. Sternites (PI. V, fig. 65) with four setigerous areas, 

 the median pair a little anterior to the posterior pair, one on either side of the 

 median line, each area with two stout bristles. The above pertains to the 

 abdominal segments. On the dorsum and lateral portions of the anterior ring 

 of the prothorax at about mid-length there are about ten setigerous areas, the 

 median pair close together and bearing a single seta, the next pair more 

 widely separated, each with two short setae; the third pair closer to the 

 second pair than they are to one another, likewise with two setae, one long 

 slender bristle and a shorter slender one; lateral setae solitary, long and stout, 

 two on each side of the prothorax. The meso- and meta-thoraces at about 

 midlength and almost in alignment have about ten setigerous punctures, the 

 inner six close together and shortest (the innermost simple, the outer two pairs 

 double); lateral bristles longer and more widely separated. 



Spiracular disk (PI. IV, fig. 49) surrounded by six short lobes, not con- 

 spicuous. Dorsal lobes short, conical, situated close together on the dorso- 

 median line, divergent apically, broad at the base, tapering rapidly to the acute 

 tip. Lateral lobes longest, elongate-conical, tapering to the rather acute apex. 

 Ventral lobes short, broad, and blunt with a broad blackish blotch on the inner 

 face, in the smaller specimen occurring as two parallel transverse lines beneath 

 each spiracle. Gills short, blunt, dark in colour. 



This is probably a species of Tipula rather than the related genus, Neph- 

 rotoma, but the immature stages of the two genera are very similar to one another. 



EXPLANATION OF PLATE L 



Fig. 1. Wing of Dicranomyia alascaensis, n. sp. 



2. Erioptera (Erioptera) angustipennis, n. sp. 



" 3. Limnophila (Dactylolabis) rhicnoptiloides, n. sp. \ 



" 4. Tricyphona brevifurcata, n. sp. 



"5. T. frigida, n. sp. 



" 6. Nephrotoma arcticola, n. sp. 



" 7. Stygeropis parrii (Kirby). 



"8. S. parrioides, n. sp. 



" 9. Tipula diflava, n. sp. (pattern omitted). 



" 10. T. arctica Curtis. 



" 11. T.johanseni,n.sp. 



EXPLANATION OF PLATE II. 



Fig. 12. Antenna of Stygeropis parrii; basal and apical segments. 



"13. S. parrioides; the same. 



" 14. Nephrotoma arcticola; basal segments. 



" 15. Tipula johanseni; the same. 



" 16. T. diflava; the same. 



" 17. T. arctica; the same. 



" 18. T. subpolaris; the same. 



" 19. T. besselsoides; the same. 



" 20. Hypopygium of Tricyphona frigida; pleurite and appendages, dorsal aspect. 



" 21. T. diaphana (Doane); the same. 



" 22. Stygeropis parrioides; outer pleural appendage. 



" 23. S. parrii; the same. 



" 24. S. parrii; inner pleural appendage. 



" 25. S. parrioides; the same. 



" 26. S. parrii; ninth tergite, dorsal aspect. 



" 27. S. parrioides; the same. 



