1'76 DIPTERA OF NORTH AMERICA. [PART IV. 



Gen. XXII. PSILOCOXOPA. 



This European genus being but imperfectly known by me, I 

 have to confine myself to the remarks already given about it in 

 the genus Gnophomyia (compare p. 173). 



Gen. XXIII. GOXIOIWYIA. 



Two submarginal cells ; the Jirst very short, suhtriangular, owing to the 

 shortness and the oblique direction of the anterior branch of the second 

 longitudinal vein (Tab. II, fig. 4, wing of G. subcmerea ; fig. 2, G. sidphu- 

 rella) ; no marginal cross-vein ; four posterior cells ; discal cell open or 

 closed ; when open, it is coalescent with the third posterior cell ; wings 

 glabrous. Antennae 16-jointed, rather short. Feet long, slender; tibife 

 without spurs at the tip, tarsi with distinct empodia. Forceps of the male 

 with several branches and linear appendages (Tab. IV, fig. 17, forceps of G. 

 hianda ; fig. 18, of G. cognatella). Ovipositor of the female slender, arcuated. 



Rostrum and palpi short ; the joints of the latter nearly of 

 equal length. The antennae, if bent backwards, would not reach 

 beyond the root of the wings; the joints of the flagellum arc 

 short subcylindrical or oval, verticillate ; in G. sulphurella the 

 basal joints in the male are strongly incrassated. The feet are 

 more or less pubescent ; sometimes this pubescence is hardly per- 

 ceptible. The Avings vary in length ; they are comparatively 

 short in G. sulphurella (Tab. II, fig. 2), and longer in G. sub- 

 cinerea (Tab. II, fig. 4) and hianda. The venation has many 

 striking peculiarities ; the tip of the auxiliary vein is nearly 

 opposite the origin of the second longitudinal vein, often a little 

 before or a little beyond it ; never so much beyond it as in the 

 other Eriox)terina ; the subcostal cross-vein is at this very tip {G. 

 suhcinerea, cognatella, sulphurella), or quite near it {G. hianda). 

 The prififurca originates about the middle of the anterior margin ; 

 it is more or less arcuated ; the first submarginal cell is very short ; 

 its petiole being long and its inner end being posterior to the tip 

 of the first longitudinal vein, or at the utmost, nearly opposite 

 this tip {G. hianda)) the anterior branch of the second longi- 

 tudinal vein is short, running obliquely towards the costa and 

 reaching it at a short distance beyond the tip of the first longi- 

 tudinal vein, or at this very tip {G. hianda) ; this course of the 

 anterior branch of the second longitudinal vein gives to the first 

 submarginal cell a triangular shape ; the marginal cross-vein is 



