214 THE CANADIAN ENTOMOLOGIST 



THE NORTH AMERICAN SPECIES OF THE ANTHOMYIID GENUS 

 HEBECNEMA SCHNABL (DIPTERA). 



BY T. R. MALLOCH, 

 Urbana, 111. 

 This genus differs from HcUna R.-D., to which it is most closely allied, in 

 having the prealar l)ristle absent, arista invariably plumose, fifth abdominal 

 sternite in male with a deep U-shaped posterior excision, and the female genitalia 

 without a pair of long slender apical processes. 



Key to Species. 



1. Species entirely fulvous yellow . .fiilva Bigot 



Species with thorax and abdomen entirely black 2 



2. All femora and tibiae reddish yellow pallipes Malloch 



Mid and hind femora and all tibiae reddish yellow nigricolor Fallen 



All femora and usually tibiae also black 3 



3. Abdomen without a dorsal central black vitta, sometimes with one or two 



pairs of very indistinct blackish spots fumosa Meigen 



Abdomen with a very distinct dorsocentral black vitta 4 



4. Halteres with black knobs ; abdomen in female entirely glossy black with- 



out pruinescence vespertina Fallen 



Halteres with yellow knobs ; abdomen in female with distinct gray 

 pruinescence 5 



5. Male abdomen broadly ovate, with pearlaceous gray pruinescence, and an 



almost linear black dorsocentral vitta ; mid femur with a few long fine 

 bristles at base on posteroventral surface ; head hardly flattened above ; 



eyes hairy umbratica Meigen 



Male abdomen narrowly ovate, with brownish gray pruinescence, and a 

 broad black dorsocentral vitta which tapers posteriorly ; mid femur 

 without distinct bristles basally on posteroventral surface; head of male 



distinctly flattened above; eyes bare affinis, sp. n. 



I have included fumosa and nigricolor though so far they have not been 

 recorded from this country. It is, however, not improbable that they will ulti- 

 mately be found to occur either in New England or the northwest. 



Hebecnema affinis, sp. n. 



Male. — Black, almost glossy. Thorax and abdomen with brownish gray 



pruinescence, the former very indistinctly vittate, the latter with a broad, black, 

 dorsocentral vitta which tapers posteriorly. Legs black, the tibiae paler. Wings 

 infuscated, more conspicuously so basally and anteriorly. Calyptrae whitish 

 yellow. Halteres yellow. 



Head rather conspicuously flattened above ; eyes bare, separated at 

 narrowest part of f rons by a distance equal to width across anterior ocellus ; each 

 orbit with three or four bristles and some weak hairs anteriorly; parafacials 

 almost mvisible from the side ; third antennal segment over twice as long as 

 second; longest hairs on arista longer than width of third antennal segment. 

 Thorax normal. Abdomen narrowly ovate ; basal sternite in type with a few 

 hairs, in other specimens bare; fifth sternite normal. Legs as in vespertina, 

 except that the mid femora lack distinct bristles basally, and there are two antero- 

 ventral bristles on hind tibia. 



Female. — Very similar to the female of umbratica, but the eyes are bare 



