172 PROC. ENT. SOC. WASH., VOL. 20, NO. 8, NOV. 1918 



foveae elongate, narrower below; ocellar basin pentagonal in outline, but 

 the lower wall nearly obsolete; antennal furrows interrupted above the 

 frontal foveae; postocellar area sharply defined, uniformly convex, but 

 little wider than long; third and fourth antennal joints subequal; stigma 

 about three times as long as its greatest width, regularly rounded below; 

 nervulus received in the middle of the discoidal cell. Black; palpi and 

 tegulae, whitish; legs below the coxae pale ferruginous; sides of the tergites 

 3, 4, and 5, and most of the sternites with ferruginous spots; wings subhya- 

 line, venation dark brown. 



The above description is taken from a number of males col- 

 lected at Boulder, Colorado, May 22, 1907, by S. A. Rohwer, in 

 the foliage of Alnus tenuifolia, Populus angustifolia, and Salix 

 luleosericea. 



Genus Platycampus Schi0dte. 



This genus is divided into two subgenera on the dentation of 

 the claws. 



Tarsal claws simple Anoplonyx Marlatt 



Tarsal claws with an inner tooth Platycampus Schi0dte 



Subgenus Platycampus Schi0dte. 



Platycampus Schi0dte, Mag. Zool., vol. 19, 1839, p. 20 (footnote). 

 Camponiscus Newman, Ent., vol. 4, 1869, p. 215. 

 Erasminus Gistel, Naturg. d. Thierreichs 1848, p. IX. 

 Leptopus Hartig, Fam. Blatt. Holzwesp., 1837, p. 104, (non Latreille, 

 1809). 



Four species of the genus Platycampus are known to occur in 

 the Nearctic region: 



Platycampus albostigmus (Rohwer). 



Camponiscus albostigmus Rohwer, Journ. N. Y. Ent. Soc, vol. 16, 1908, p. 

 105. 



Type. University of Nebraska. 



Distribution. Ute Creek, Costilla County, Colorado. 



Platycampus americanus (Marlatt). 



Camponiscus americanus Marlatt, Can. Ent., vol. 28, 1896, p. 251; Dyar, 

 Journ. N. Y. Ent. Soc., vol. 5, 1897, p. 24. 



Type. Cat. No. 3471, U. S. Nat. Mus. 



Distribution Jefferson, New Hampshire. Type material 

 reared from larvae collected on poplar by H. G. Dyar. 



