84 MAINE AGRICULTURAI, EXPERIMENT STATION. I912. 



North Mt., Pa., North Adams, Mass., (C.W.J.) June; Laval- 

 lette, N. J., (Vierick) May; Ithaca, N. Y. ! August. 



Var. a. Female. Length 3.7 mm. Thorax dark brown, 

 humeri and lateral margins of the mesonotum reddish yellow ; 

 abdomen blackish. ]\It. Constitution, Orcas, Id. Wash.. 

 (J.M.A.) Juty. 



31. Genus Mycetofhila Meigen. 



Illiger's Mag. II. 263, 1803; Klass, I, 90, 1804. 



Pungivora Meigen, Nouv. Class. 16. 1800, (without type). 



Head placed low on the thorax so that in profile it makes a 

 continuous curve with the thorax, ocelli 2, placed close to the 

 eye margin. Legs stout, tibial seta; stout, those of the hind 

 legs longer than the greatest diameter of the tibia. Costa not 

 produced ; subcosta short, incomplete ; cubitus forks nearl}) 

 under the fork of the media, its branches nearly parallel apical- 

 ly; anal vein incomplete. The larvae, wdiich are commonly 

 found in decaying wood and in fungi, possess transverse rows 

 of microscopic ambulacral setulse upon the margins of the seg- 

 ments of the venter. 



The following table should be considered only as a guide ; 

 and if a specimen be found which cannot be placed, it must not 

 be assumed undescribed without making a careful study of the 

 hypop3'gium, the most reliable single character. Color and 

 wing markings, and possibly even the number of the setae of 

 the middle tibia are subject to occasional variation. 



Tabic of Species. 



a. Three ranges of setse on the extensor surface of the hind tibia, and 

 with 2 or more setae on flexor surface of middle tibia, 

 b. Wing without a distinct cloud, though the petiole of the media 

 itself may i^e darkened, 

 c. Thorax subopaque, humeri and posterior lateral angles yellow;' 

 female. i. exstincta. 



cc. Thorax shining black; hypopygium (Fig. 69"). 



2. jncunda n. sp. 

 bb. Wing with distinct spots or cloud. 



c. Wing with a single spot which covers the crossvein. 



d. With 2 setae on flexor surface of middle tibia ; hypopygium 



(Fig. 70). 3. perita n. sp. 



dd. With 3 setae on flexor surface of middle tibiae; hypopygium 



(Fig. 68). I. exstincta. 



