112 THE CANADIAN ENTOMOLOGIST. 



Mycetophilidae among themselves exhibit much difference in utiHty and 

 beauty, the former quality being exemplified by Mycetophila with its 

 skipping and shuffling movements ; the latter by the graceful form of 

 Macrocera when it rests on a shady paling. The four following sub- 

 families of Mycetophilidae are distinguished from the others by each of 

 them including more than one genus : 



Sub-family Mycetobin^. 



A — Brachial vein and cubital vein forming a sessile fork. . . i Mycetobia 

 B — Brachial vein and cubital vein forming a petiolated fork, 

 a — Base of this fork nearer to the base of the wing than is 



the base of the 2nd hind areolet 2 Ditomyia 



b — Base of this fork more distant from the base of the wing 



than is the base of the 2nd hind areolet 3 Plesiastina 



Sub-family Ceratoplin^. " 



A — Mouth elongated like a beak i Asindulum 



B — Mouth not elongated like a beak, 



a — Antennae dilated ; palpi not bent together 2 Ceroplatus 



b — Antennae not dilated ; palpi bent together 3 Platyura 



Sub-family ScioPHiLiNiE. 



A — Costal vein extending to the tip of the wing i Sciophila 



B — Costal vein not extending to the tip of the wing. 



.a — Base of the 4th hind areolet much nearer to the base of 



the wing than is the base of the 2nd hind areolet 2 Empheria 



b — Base of the 4th hind areolet a little nearer to the base of 

 the wing than is the base of the 2nd hind areolet. 



* — Second hind areolet with a very long petiole 3 Polylipta 



* * — Second hind areolet with a moderately long petiole 5 Empalia 



•c — Base of the 4th hind areolet in a transverse line with the 

 base of the 2nd, or very near the base of the 

 wing 6 Tetragoneura 



d — Base of the 4th hind areolet much more distant from the 

 base of the wing than is the base of the 2nd hind 

 areolet 4 Lasiosoma 



Sub-family Mycetophilinte. 



A — Three ocelli on the front. 



-2L — Abdomen with seven segments. 



