242 
Wisconsin Academy of Sciences, Arts, and Letters. 
Helophilus 
Table of species 
1. Face, between oral opening and base of antennae, with a bare 
shining stripe, without pile or pollen... 
Face without such shining stripe, entirely covered with pollen. 
t. Abdominal bands on third and fourth segments distinctly in* 
terrupted or entirely absent; facial stripe deep black- 
shining . 
Abdominal bands on third and fourth segments always present, 
usually not interrupted; facial stripe light-colored, or at 
most reddish, not entirely black..... 
3. Pile of scutellum entirely yellow, fourth abdominal segment 
black, without yellowish spots or bands...... bruesi 
Pile of scutellum black on disk, fourth segment with spots or 
whitish cross-band ..... obscurus 
4. First two joints of antennae black, third usually so; front of 
female black pilose only near the ocelli, front of male 
broad . latifrons 
First two joints of antennae reddish, third reddish at least 
on the under side; front of female black pilose, front of 
male narrow above ... similis 
>5. Antennae entirely reddish or yellowish..... 
Antennae dark, at least first two joints blackish. 
6. Abdomen oval, larger yellowish species, with distinct yellowish 
cross-bands, femora mostly yellowish. laetus 
Abdomen more slender, with nearly parallel sides; darker 
species, cross-bands more whitish. 
7. Hind coxae of male with a long, stout process below; only a 
slight indication of this spur in female; abdominal cross¬ 
bands of female attain lateral margin. chrysostomus 
Hind coxae without such protuberance. 
8. Third and fourth segments of male mostly black-shining, spots 
small or indistinct; cross-bands on third segment of female 
do not attain lateral margin (if so only slightly), hind 
femora of female with long black spots. bilinearis 
Third and fourth segments of both sexes with interrupted lunate 
cross-bands which distinctly attain side margins; hind 
femora of female largely yellow. lunulatus 
9. Face jutting forward into a sharp cone, first and second joints 
of antennae black, third yellowish red.... conostomus 
Face not jutting forward into a sharp cone, only moderately 
produced ..... 
10. Abdomen velvet-like black, each segment with a triangular 
black-shining spot in the middle, and a hoary spot on each 
side . porcus 
