172 NEW NORTH AMERICAN ANTHOMYIIDAE (dIPTERa) 



Hydrophoria coloradensis sp. n. 



j/„/(.._.Siniilar to the preceding species in color, differing in having the 

 base of radius yellowish, and the dorso-central abdominal vitta more dis- 

 tin(;tly tapered apically. Thorax with at least one pair of well developed 

 l)resutural acrostichals; mesopleura with three or four bristles near anterior 

 ui)per angle. The costal thorns are smaller than in flavohaUemta, and the 

 fifth sternite more densely hairy. Length, 6 mm. 



Tupc—d"; Tennessee Pass, Colorado, July 25, 1917, [Coll. 

 Aidrifh]. 



Thi.'^ species may ))e imda Sohnaljl. 



Hydrophoria borealis sp. n. 



Male.— Color darker than in uniformis, and similar to that of flavohallcrata. 

 Eyes separated by a distance at least as great as width acro.ss posterior- 

 ocelli; parafacial in profile at base of antennae distinctly broader than third 

 antennal joint; hypoplem-a bare; fourth tergite with a tuft of fuscous bristly 

 hairs on each posterior lateral angle; processes of fifth sternite broad, fringed 

 along the inner margins with fine hairs, the disc with a few bristly hairs. 

 Hind femur with a .series of long, slender bristles on basal half of postero- 

 ventral surface. 



/^e»?.a/c.— Similar to the male in color, but not readily separable from 

 flavohaltcrata. Parafacial in profile but little narrowed below, as wide as 

 third antennal joint for almost its entire length. Hind femur with .several 

 long hair-like bristles at base on postero-ventral surface. At least one of 

 the costal thorns long and consi)icuous. sometimes as long as inner cross- 

 vein, or nearly so. 



Length, 5 to G.2o mm. 



Type.— cf; Katmai, Alaska, June, 1917, (J. S. Hine), [Coll. 

 Hine]. Allotype. — 9 ; same locality as type. Paratypes. — 1 cf, 

 topotypieal; eleven specimens, Mt. Constitution, Washina;ton, 

 July 17. 1909, [Coll. Dr. Aldrich]. 



Hydrophoria elongata sp. n. 



Male. — Differs from the preceding species and ambigua in having the 

 abdomen more -brownish gray and with a very indistinctly limited dorso- 

 central vitta. 



The eyes are .separated by a space at least equal to width across posterior 

 ocelli; the arista has the longest hairs about equal in length to width of third 

 antennal joint; parafacials but little narrowed below, as wide as third an- 

 tennal joint; apical jjortion of probo.scis stouter than in borealis. Thorax 

 with one or two pairs of presutural acrostichals. Abdomen more distinctly 

 tapered than in other species, the second tergite very noticeably longer than 

 tliird, tlic latter about twice as long as fourth; fifth sternite glossy black, 

 almost- entirely bare on disc of jn-ocesses, their inner margins with a fringe 

 of liairs. Fore tibia with one or two posterior l)ristles, one of which is longer 



