8 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 65. 



black bristles, and on the hind side with long curved hairs, which 

 latter are more dense near the tip and curl up to the shape of a lock 

 of hair. Hind tibiae plain, scarcely stouter than the middle tibiae ; 

 on the upper side, not far from the basis, there is a strong bristle, 

 and on the latter half a few small bristles; the under side is beset 

 with short small bristles, which are isolated upon the first part and 

 closer together and in more regular order upon the second half; at 

 the end of the under side there is a considerable number of less 

 strong and less short bristles, of which the last is distinguished by its 

 greater length ; on the outside of the tip of the tibiae there are several 

 short and one longer and curved bristle, which has almost the thick- 

 ness of a thorn. Tarsi plain, the joints of decreasing length, the 

 first joint of the fore and of the middle tarsi with more, that of the 

 hind tarsi with less bristles. Halteres yellowish-brown, the lower 

 part of the knob more dark. The wings of uniform breadth and at 

 the end more rounded than in the other species; an uncommonly large 

 black spot covers their apical half with the exception of a broad gray 

 border on the posterior margin, and extends as a broad cloud along 

 the fifth longitudinal vein almost as far as the anal cell; inside of 

 the di-scoidal cell it is somewhat paler, otherwise, however, so dark 

 that the two black spots, peculiar to this genus, upon the posterior 

 transverse vein and upon the last segment of the fourth longitudinal 

 vein, can only be perceived when the wing is held toward the light ; 

 the anterior part of the wing from the basis as far as the middle is 

 dingy- whitish hyaline ; the anal angle and a broad border along the 

 posterior margin are more hyaline-gray." 



Hahitat. — Fort Kesolution, Hudson Bay Territory (Kennicott). 



"''Female. — It is distinguished from the male by the following 

 characters: Face with pale yellow-grayish, front with brown dust. 

 The middle of the upper side of the thorax witli yellow-brownish 

 dust, marked with a few spots of whitish dust. Its lateral stripes 

 are covered with brown, the edge of the lateral margin, however, 

 again with gi-ay-whitish dust. The abdomen is more green, less 

 coppery and less bright than in the male. The dust upon the pleurae 

 and upon the fore coxae is less yellow. The fore femora are of a 

 similar structure as those of the male ; the fore tibiae without a thorn 

 on the inside, elongated at the tip in a much smaller and sharper 

 tooth, before which there is no excision ; otherwise the feet are plain, 

 the middle and hind femora straight and much more slender than in 

 the male; middle and hind tibiae only sparsely beset with scattered 

 bristles. 



" Observation. — As I do not possess a North Ajnerican female of 

 S. spinipes, I have prepared the above description from Swedish 

 siDecimens." 



Type locality. — Lapland. Also from Hudson Bay Territo4-y. 



