230 Wisconsin Academy of Sciences, Arts, and Letters. 
Platychirus St. Fargeau and Serville 
(Table of females, after Verrall) 
1. Antennae absolutely without yellowish markings beneath the 
base of the third joint. 2 
Antennae partially yellow, at least beneath the base of the 
third joint . 7 
2. Hind legs with at least a distinct dark band on the femora and 
tibiae . 3 
Hind legs entirely orange, without the faintest trace of any 
dark markings on at least the hind femora. 6 
3. Paler species, with usually only a slight dark ring on the hind 
femora and tibiae . 4 
Darker species, with usually conspicuous blackish markings on 
the hind femora and tibiae, but this character not a very 
safe one... 5 
4. :Larger species; frontal side dust spots golden and well de¬ 
fined (I have been unable to make use of this character).. 
. scambus 
(Smaller species; frontal side dust spots grey and ill defined.. 
. immarginatus 
5. Larger species; side dust spots on the frons moderately 
large . Tiyperboreus 
Smaller species; side dust spots on the frons small, angustatus 
6. Abdominal spots distinctly reddish and separated by a broader 
black median line and black cross-bands. quadratus 
Abdominal spots distinctly yellowish and separated by nar¬ 
rower black lines . perpallidus 
7. Hind legs entirely yellow, at least on the femora and tibiae.... 
. quadratus 
Hind legs black or brown. peltatus 
32. P. angustatus Zett. Two males at Madison, May and August. 
33. P. Tiyperboreus Staeger. Sheboygan, Manitowoc, Yilas, Pierce, 
Dane, Portage, Milwaukee, Washington, Burnett, and Polk 
Counties. May to October. Very closely related to, if 
not the same as, clypeatus Meig. 
34. P. immarginatus Zett. Fond du Lac and Dane Counties. 5 
males. Figure 27. June to September. 
35. P. peltatus Meig. Price, Vilas, Milwaukee, Sheboygan, Wash¬ 
ington, Dane, and Pierce Counties. Mostly late summer. 
Figure 28. 
36. P. perpallidus Verrall. Barron, Dane, and Fond du Lac 
Counties. May to September. 
