82 DIPTERA OF NORTH AMERICA. [PART IV. 



The remaining portion of the wing is clouded with brown, as in 

 the three preceding species, only these clouds are darker. 



Hah. Slave Lake, H. B. T. (Kennicott). 



I have only a single female, the feet of which are broken off and 

 the abdomen somewhat injured in its coloring. The infuscated 

 knob of the halteres and the coloring of the intermediate stripe 

 of the thorax prove the relationship of this species to L. solitaria. 

 The structure of the antennae, the joints of which are compara- 

 tively shorter and stouter in L. hudsonica, and that of the ovi- 

 positor, which is not so broad at the basis, prove to my satisfaction 

 that this is not a darker variety of L. solitaria. The anterior 

 branch of the fork, formed by the tip of the auxiliary vein with 

 the subcostal cross-vein, is longer than the posterior one. 



In the Proc. Acad. Nat. Sci. Fhilad. 18C1, p. 290, I have tried 

 to establish diiferences between the four above described, closely 

 allied species, based upon the shape of the fork formed by the 

 tip of the auxiliary vein with the subcostal cross-vein. These 

 differences are not entirely reliable, however, as I have had 

 occasion to convince myself since. I possess, moreover, several 

 northern specimens of a doubtful character, which prove either 

 that the number of the species belonging here will have to be 

 enlarged, or that the typical forms of the species, such as I have 

 described them, undergo considerable modifications. 



5. li. triocellaf a 0. S. % and 9 • — Flavo-ferruginea, tliorace lineis 

 et punctis nigris ; als flavescentes, ocellis tribus parvis fuscis ; venula 

 transversa marginalia juxta apicem primae longitudinalis sita. 



YeUowish-ferruginous, thorax with black lines and dots ; wings yellowish, 

 with three small brown eye-like spots ; marginal cross-vein at the tip 

 of the first longitudinal vein. Long. corp. 0.35 — 0.4. 



Syn. Limnobia triocellata 0. Sacken, Proc. Ac. Nat. Sc. Phil. 1859, p. 213. 



Rostrum and palpi brown ; antennte pale ferruginous-yellow ; 

 front slightly hoary ; vertex yellow. Thorax ferruginous-yellow, 

 shining above ; collare long, with a longitudinal brown stripe in 

 the middle ; on the mesonotum, two short, brown lines near the 

 collare and four brown spots before the suture ; a brown dot on 

 the humerus ; pleurse yellow, slightly hoary, with two or three 

 brown dots between the fore coxse and the root of the wings ; 

 between the thoracic suture and the scutellum, two brown lines 

 in the middle and a dot on each side ; metathorax with brown 



