AMERICAN DIPTERA. 13 



])ile. ;iih1 on the other joints it is parted so as to form two rows; the 

 joints arc wholly wanting in the black bristles, and the black disk of the 

 middle pair is very broad. The female is difficult to distinguish from 

 praepes, but the front tarsi are not so slender, and on the sides of the 

 dorsum of the thorax, in front of the suture there is a large brown pol- 

 liuose spot which is wholly shining in praepes. There can be scarcely 

 a doubt of the distinction of the two species, but I do not give it a name 

 till larger collections have been examined. 



16. Cyrtopogoii prof'usiis, 0. Sacken West. Dipt. .305. 



A male from New Mexico (irom IMr. E. Keen) agrees very well with 

 the description. 



17. Cyrtopogoii nugator Osten Sacken, West. Dipt. ."07. 



A male and female from Mt. Hood. The male has the second and 

 third abdominal pollinose cross-bands narrowed in the middle, but entire. 



18. Cyrtopogoii n. sp. 



In size, shape and abdominal markings resembling (\ nngaf or, hut the 

 markings of the thorax obscure and the ungues black. The body is 

 almost wholly without pile, except the thin white beard ; the face has 

 sparse black bristles, the dorsum of thorax and scutellum bare, except a 

 row of bristles on each side of the former, and two on the border of the 

 latter ; the abdomen wholly bare, black, .shining except the interrupted 

 cross-bands on segments 1-6, the femora are bare, the tibiae and tarsi 

 only with black bristles. The fan-like row of bristles in front of the halteres 

 is black, and the species would be sought for under posititious or mdator 

 of Osten Sacken's synoptical table. Washington Territory. 



1<). Cyrtopogon diibiiis n. sj). 



9 .— Scutelliini llatteiieil, gray pollinose above: a})(loiiien shining black, first 

 segment on the sides, and llie four following with interruj)ted posterior cross-bands 

 of gray pollen: femora black, tibiae and tarsi dark red; head, except the beard, 

 wholly black pilose, antennae black: wings with narrow brown clouds on the 

 cross- veins. Length 11 mm. 



Face thickly whitish pollinose and densely black pilose, beard below white, on 

 the sides and above black. Dorsum of thorax deep blackish brown with dense 

 gray pollinose markings as follows: A slender median stripe obsolete behind ; a 

 large spot in front of the scutellum, slenderly prolonged on its anterior angles to 

 the middle of the dorsum, the humeri, a spot on their inner sides, another large 

 one behind, concave on its inner border, and a smaller one on the post-alar 

 c.iUosities. Tleurae gray pollinose; the fan-like fringe of hairs in front of the 

 halteres black. Abdomen with white pile on the sides in_ front; the last two seg- 

 ments wholly shining. Anterior and middle coxae, and all the femora below 

 towards the base with long soft white pile: front tibiae on their inner sides and 

 their metatarsi with golden pubescence; hind tibiae at their tip and the tip of 

 their metatarsi with white pubescence, femora black, tibiae and tarsi dark red, 



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