70 THE CANADIAN ENTOMOLOGIST. 



8. Femora yellow formosa, Coquillett. 



Femora black 9. 



9. The humeral cross-band enclosing a hyaline triangle in 



front fausta, Osten Sacken. 



The humeral cross-band not enclosing a hyaline triangle. intrudens, n.sp. 

 Rhagolctis intra dan, n. sp. 



Shining black ; the following parts yellow : Front, face, antennae, 

 except apical part of arista, palpi, proboscis, cheeks, humeri, a streak from 

 the humerus to the wing below the dorso-pleural suture, scutellum, 

 halteres, all the legs, except coxae and femora. Wings as figured, the 

 veins whitish in the pale portions and blackish in the rest ; the pale 

 portions of the membrane are distinctly white, not transparent except 

 close to the margin ; anal cell with only a blunt point ; first vein distinctly 

 hairy to the tip. 



Chetotaxy : Postvertical pair of bristles rather large, conspicuously 

 white, all other bristles black: vertical 2, orbital r, fronto-orbital 2 

 reclinate, lower fronto-orbital 3 cruciate, on lower edge of cheek 1, 

 humeral 1, notopleural 2, dorsocentral 1 (behind the suture, there may be 

 another where the pin is inserted), presutural 1, supra-alar 3, post-alar o, 

 scutellar 2, mesopleural 2 (on the posterior edge), pteropleural 1, sterno- 

 pleural 1. 



Abdomen uniform shining black, with rather coarse hairs, larger on 

 the posterior margins of the segments ; on the posterior margin of the fifth 

 segment a row of well-developed bristles \ sixth segment a little longer 

 than the fifth, hairy ; ovipositor retracted in the described specimen. 



Third joint of antenna reddish, with an acute upturned point at end ; 

 arista pubescent; palpi with a few black hairs at tip. 



Length, 4.1 mm.; of wing, 3.9 mm. 



Described from one female specimen with the following label : 

 "6.3142. W. R. Palmer, Victoria, B. C. Emerged at Ottawa, 19, VI, 

 1907." 



It is highly probable that the same species occurs in the vicinity of 

 Kendrick, Idaho, as I have found late sour cherries there considerably 

 affected with a dipterous larva, which I have not reared. 



A few words on the economic relations of the species may be worth 

 while. The habits of but four species of our fauna are known ; all these 

 species are figured in the accompanying illustration, the pattern of the 

 wing being sufficient to separate them. All the drawings are on the same 



