AMERICAN DIPTERA. 303 



segment, very assymetrical, strongly compressed to right with distinct 

 cleft and a little developed vertical keel at apex ; intermediate and 

 ventral lobes small and black. Coxae black ; femora yellow, stout ; 

 apical half of posterior pair strongly incrassate (Fig. 121) where they 

 are generally discolored with brown, their flexor surfaces very sinuate; 

 all bearing the usual series of spines apically, which are very distinct ; 

 middle femora with posterior series of yellow hairs which become 

 minute black bristles apically ; post-tibia strongly bent at apical third ; 

 apical and basal post-tarsal joints in proportion 1:3.5, Wings faintly 

 tinged with brown, with colored stigma (Fig. 157). Length, 4.4-5.0 

 mm. ; wings, 5.5-6.3 mm. 



9. Similar. Front white ; ocellar tubercle shining black. Thorax 

 cinereous ; mesonotum somewhat shining, brown pollinose medianly, 

 sparingly pubescent. Abdomen with lateral apical margins of 2-5 

 faintly and narrowly yellowish. Ovipositor yellow, short and stout, 

 reaching third ventral segment (Fig. 93), gradually tapering from its 

 elongate shining black base. Tibia? dilated apically, especially poste- 

 rior pair which are rather distinctly bent ; post-tarsi nearly equalling 

 tibiae, serrate with basal joint hardly more than twice as long as wide ; 

 apical joint of all tarsi blackish. Colored stigma longer than third 

 section. 



Type— 6". Mt. Ascutney, Vt., July 11, '08, 2000 ft. alt. 

 (Figs. 10, 92, 121, 157, Johnson, B. S. N. H.). 



Paratypes. — Mt. Ascutney, Vt., 1 c? ; Brookline, Mass., 1 

 cf ; Freetown, Mass., 1 9 , Fig. 93 (all by Johnson, B. S. 

 N. H.); Ithaca, N. Y. (2 cfs, coll. Banks). Taken in July. 



May be distinguished from its allies by the thickened 

 femora and yellow legs. 



25. P. brevis n. sp. 



9 . Front and face silvery, only extreme vertex shining ; occiput 

 white; second antennal joint brown, third yellow, long white acumi- 

 nate (Fig. 37). Mesonotum subopake, brownish medianly, cinereous 

 laterally, Scutellum not shining, brownish-black, without hairs ; 

 humeri black, halteres yellowish, apex of knobs brown. Pleurae and 

 metanotum cinereous. Abdomen shining to subopake, grayish tinge 

 at apices of segments ; apical margin of first broadly white and broadly 

 interrupted medianly ; entire lateral margins of second and apical 

 lateral angles of following segments, cinereous ; fifth segment longer 

 than sixth. Ovipositor yellow, gradually tapering from the elongo- 

 globose, cinereous base, straight or slightly curved down (Fig. 79), 

 extending to base of second ventral segment. Legs yellow, coxae, 

 broad median rings on femora, and apical tarsal joints blackish ; inner 

 surface of post-femora polished ; post-tibiae normal; apical and basal 



TRANS. AM. ENT. SOC, XXXVI. JANUARY, 1911 



