J. R. MALLOCH 1()9 



which extends from base to apex, posterior surface with closely i)laced long 

 bristles, those on jwstero-ventral surface shorter and weaker than the antero- 

 ventral series; hind tibia with two dorsal, one antero-dorsal and three antero- 

 ventral bristles, the latter decreasing in length from ujjper to lower; hind 

 coxae bare above. Third and fourth veins decidedly convergent ai)ii'ally. 

 Sciuamae subequal. Length, 4.5 mm. 



Type. — cf ; Augorville Woods, near Ui'hana, Illinois, March .'^0, 

 I!)18, (J. R. Mallooh), [Illinois]. 



This species is related to hirticep.s Stein, but differs in the 

 armature of the hind legs. 



Hydrophoria nigerrima sp. n. 



Mdle and fcfiialc. — Deep black, distinctly sliining. Thorax in male with- 

 out distinguishable vittae, indistinctly trivittate in female. Abdomen in 

 male with the dorso-central vitta so broad that it covers almost the entire 

 dorsum; in female nuich narrower. Wings in male slightly infuscate. Hal- 

 tcres black in both sexes. 



Male. — Eyes separated by more than width across j)osterior ocelli; orbits 

 with very long bristles on entire length; longest hairs on arista not as long 

 as widtli of third antennal joint; parafacial in profile wider than tliird an- 

 teniial joint and more than half as wide as height of cheek, the latter wilh 

 iHunerous long, slender bristles on margin, some of these extending above 

 vibi-issa. The portion of fourth tergite (third visible) which overlajis is ven- 

 trally rather densely bristled; fifth sternite with numerous rather long hairs, 

 the inner margin of each process basally with a fringe of long setulose hairs. 

 Hind femur with a series of long slender bristles on almost the entire length 

 of postero-ventral surface; hind tibia with from five to seven bristles of un- 

 equal lengths. Costal thorn small. 



Female. — Differs from the male in having the eyes separated by about 

 one-half the head-width, the orbits densely hairy, with at least one supra- 

 orbital forwardly directed, and one pair of cruciate bristles and a few hairs 

 on interfrontalia. The abdomen is jjointed at apex, and there are no ai:)ical 

 tliorns. 



Length, G to 7 mm. 



Tijpe.— d^; Mt. Rainier, Washington, 7000 to 9000 feet, on 

 snow, August, 1917, (A. L. Melander). Allotype. — 9 ; same data. 

 Paratypes. — Seven specimens, same data as type; two mak^s and 

 two females, Paradise Park, Mt. Rainier, August, 1917, (A. L. 

 Melander) ; one male, one female, Mt. Rixford, California, on snow, 

 August 12, 1914, (Coll. Aldrich). 



The type has been returned to Professor Melander, and para- 

 types have l)een placed in the collections of the AcadtMuy of 



TRANS. AM. ENT. SOC, XI.VI. 



