38 Psyche [March 
Described from one male taken at Niagara Falls, Ontario, 
July 17, 1921, by the author. 
Type in the author’s collection. 
Table of North American species of Medeterus. 
1 Scutellum with one pair of bristles, there may be a small pair 
of hairs outside of these 2 
Scutellum with two pair of bristles, the outer pair may be 
small 12 
2 Antennae, proboscis and legs, including the fore coxae, yel- 
low, (Virginia) novus Van Duzee. 
Antennae, proboscis and more or less of the femora black. ... 3 
3 Thorax with distinct vittae 4 
Thorax without distinct vittae 10 
4 Thorax with a median blue vitta, (New York) 
oibesus Van Duzee. 
Thorax with a median brown stripe running its entire 
length 5 
5 Wings with a brown cloud at base of third vein 6 
Wings without a distinct cloud at base of third vein 7 
6 Tibiae and tarsi yellow, (California) . cuneiformis Van Duzee. 
Tibiae brownish; tarsi black with the base of the basitarsus 
yellowish, (California). Female of. nitidiventris Van Duzee. 
7 Abdomen bluish with gray pollen; front in male produced 
into a four sided pyramid, (Washington) 
petulcus Wheeler. 
Abdomen shining black, or with green reflections 8 
8 Tibiae and tarsi mostly yellow, (California) 
similis Van Duzee. 
Tibiae and tarsi black, green or brown 9 
9 Last section of fifth vein only a little longer than the 
cross- vein, (California) oequalis Van Duzee. 
Last section of fifth vein one and a half times as long as the 
cross- vein, (California) nitidiventris Van Duzee. 
10 Last section of fifth vein only a little more than half as long 
as the cross-vein, (Alaska) minima N an Duzee. 
Last section of fifth vein longer than the cross- vein 11 
