THE CANADIAN ENTOMOLOGIST. 4o 



Food-plant. — Black oak {Quercus coccinea). 

 Imago. — Black ; basal, two-thirds of the wings smoky. Head densely 

 punctured ; a polished prominence behind the ocelli ; two converging 

 ridges in front, between which the lower ocellus lies ; thorax polished. 

 End of femora, all of the tibiae and tarsi of anterior and middle legs 

 white, except the last tarsal joints, which are dusky. Basal two-thirds of 

 the posterior tibise and bases of all the tarsal joints white, the 

 outer third of tibia? and tips of tarsal joints banded with dusky, 

 Forewings hyaline along outer margin for a space limited by a Hne drawn 

 from stigma to internal angle, the basal part of wing smoky-blackish : 

 veins and stigma black. Hindwings hyaline, the basal half faintly 

 smoky. Expanse of wings, lo mm. ; length of body, 4.5 mm. 



Two ? ?, Woods' Holl., Mass. 

 Strongylogaster pacificus, Macgillivray. 



Head round, pale, sordid whitish with a faint blackish, mottled line 

 from above each eye to the vertex ; eye large, round, black ; jaws dark- 

 brown ; width, about 1.5 mm. Thoracic feet large, bent outward \ abdo- 

 minal ones present on joints 6-12, 13 ; segments 6-annulate. Colour, 

 shining, translucent green, with a white subdorsal line running the whole 

 length, nearly joining its fellow at the extremities. Spiracles small, black, 

 joined by the thread-like white line of the trachete, showing by trans- 

 parency. Length, about 20 mm. 



When through eating, the larva becomes reddish and bores a gallery 

 ill a piece of decayed wood, where it remains till the following spring. 



Food-plant. — Common brake {Fteris aquilina). Larvae common in 

 June at Portland, Oregon. 

 Monostegia quercus-albce, Norton. 



Larvse bred by me on the white oak do not agree with Norton's 

 description. His characterization of the fly, however, seems to fit my 

 specimens perfectly. 



Eggs. — Deposited in the manner described by Norton ; forming small 



blisters on the underside of the leaf near the tip, separated from each 



other, each about 1.2 mm. in diameter. 



****** 



Second stage. — Head oval, brown, blackish around the eye ; mouth 

 pale ; width, 0.25 mm. 



Third stage,-^.\-S in next stage. Width of head, 0.35 mm. 



