snow: DIPTERA of COLORADO AND NEW MEXICO. 243 



Eristalis brousi Will. 



Four males and two females, Manitou Park, Colo. (Aug.); fourteen 

 males and five females, Colorado Springs (July, Aug.); two males 

 and four females, Colorado (Gillette, Nos. 822, 1331, 1722). In 

 several of [the females the lateral spots of the second abdominal 

 segments are yellow and distinct, occasionally extending a short 

 distance upon the third segment. The species occurs all over North 

 America. 



Eristalis flavipes Walk. 



A single female, Colorado (Gillette; Coll. Townsend); has a 

 broad, black pilose, posterior thoracic band. This species is well 

 distributed across the continent. 

 Eristalis transversus Wied . 



A single female, Manitou Park, Colo. (Aug.). The species is 

 recorded in Williston's Synopsis as from the Atlantic States only. I 

 have taken it also in Illinois and Kansas. 



Helophilus latifrons Loew. 



Bailey, Colo. (August); Manitou Park, Colo. (July, August); Colo- 

 rado (Gillette, Nos. 1331, 1710); Colorado Springs (August); Albu- 

 querque, N. M. (August); Las Cruces, N. M. (Townsend, June 8); 

 New Mexico (Gaumer). Not as common in New Mexico as in Colo- 

 rado. It extends across the continent. 

 Helophilus similis Macq. 



A single female specimen from Manitou Park, Colo. (August). 



Helophilus laetus Loew, 



A female from Colorado Springs (August) agrees well with Willis- 

 ton's description (Synopsis, p. 189). The fulvous band of the fourth 

 abdominal segment is subinterrupted, does not touch the anterior 

 border of the segment along its whole length, and bears a light 

 poUinose spot on the inner ends of its two halves. Previously 

 recorded east of Illinois. 



Helophilus sp. 



A female specimen from Manitou Park, Colo. (July) belongs to the 

 grcenlandicus group. From that species it shows the following differ- 

 ences: head somewhat produced, the lower border of the cheeks 

 forming an obtuse angle with the occiput; the slender median thoracic 

 stripes reach the scutellum; pile of the thoracic dorsum entirely 

 yellow; scutellum with only a few black hairs on the middle of the 

 disk; tip of the middle femora yellow. 



It differs from glacialis in the complete median thoracic stripes, in 

 the less shining color of the abdomen, which is confined to the pes- 



