128 DIPTERA OP NORTH AMERICA. [PART III. 



posteriorly it extends, although somewhat paler, along the sixth 

 longitudinal vein, which it finally crosses, as far as the posterior 

 margin of the wing, on the fifth longitudiaal vein it forms an 

 obtuse angle, at which place, on the sides of the fifth longitudinal 

 vein, it is very faint, sometimes almost interrupted ; the spot at 

 the end of the stigmatical cell coalesces with the one covering 

 the small crossvein, forming a steep, somewhat curved half-cross- 

 band; the spot covering the posterior crossvein is rather large; 

 the three other spots are of the usual shape. 



Hab. Connecticut (Osten-Sacken). 



Observation. — The name which I give to this species is intended 

 to call to mind its extraordinary resemblance to C. crassi- 

 pennis Fab., occurring in Europe. This resemblance is so great, 

 that I would doubt the specific distinctness of the two species, if 

 the femora of the American one were not altogether yellow, while 

 those of G. crassipennis are blackish-brown from the basis as far 

 as the middle. In order to overlook this difference and to main- 

 tain the identity of the two species, the proof of a perfect agree- 

 ment in all, even the minutest, plastical characters would be 

 required. The three specimens of G. similis in my possession 

 are not well preserved enough to enable me to undertake such a 

 comparison. 



4. C. canns Loew. % 9.— (Tab. VIII, f. 22.) Polline ex lutescente 

 cinereo vel albido-cinereo vestitus, tertio anteimarum articulo pedi- 

 busque fuscis, alarum macula stigmaticali et limbo venae transversalis 

 mediae separatis. 



Covered with a yellowish-gray or grayish-white pollen; third joint of the 

 antennae and the feet brown ; the spot on the stigmatical cell entirely 

 separated from the one which covers the small crossvein. Long. corp. 

 % 0.16; 9 cum terebra 0.23 ; long. al. 0.16—0.18. 



Syn. Ortalis cana Loew, Berl. Entom. Zeitschr. II, p. 374. 



Smaller than the preceding species, with a grayish or whitish- 

 gray pollen, verging less on yellow. The first two antennal joints 

 brownish-yellow or yellowish-brown ; the third joint of medium 

 breadth and rather blackish-brown. Antennal arista black. The 

 scutellum at most indistinctly yellowish-brown along the edges 

 only. Abdominal segments without any trace of darker borders. 

 The first joint of the flattened ovipositor distinctly longer than in 

 the three previous species and somewhat less broadly truncate at 



