514 



invisible.* Caiuptocladiiis is separable from OrtJiodadius, sens, lat., 

 as indicated in the generic key to Chironoinincc, by the course of the 

 posterior branch of the cubitus; but this is variable, and occasionally 

 it is doubtful to which genus a species belongs. 



I include in this paper only species belonging to the State Labora- 

 tory collection, which represents but a small portion of those occurring 

 in North America. 



TrichocIvAdius Kieffer 



Johannsen has described one North American species belonging to 

 this division, lactdpennis,^ and in the same paper assigns politus Co- 

 quillett to it. In a previous papert he states that several North Amer- 

 ican species of Orthocladius have hairy eyes, but does not give the 

 names of the species. Some species included in Camptodadiiis in this 

 paper have hairy eyes. 



I have included in my key only the species that are represented in 

 the State Laboratory collection, the early stages of which are unknown 

 to me. 



Key to Species 



1. Thorax glossy black, without pale markings; halteres black. ..... .2 



— Thorax either yellow with dark vitt£e or opaque black ; halteres pale 



3 



2. Seutelluni opaque, velvety black 1. nitidus. 



— Scutellum shining black 2. nitidellus. 



3. Thorax in both sexes glossy, bright yellow, the vittffi glossy black; 



basal joint of fore tarsi three fourths as long as fore tibiae 



3. politus. 



— Thorax black or obscurely yellowish between the vittae or on the lat- 



eral margins; basal joint of fore tarsi less than three fourths as 

 long as fore tibiffi 4 



4. Large species, 3 mm. in length ; thorax of male glossy, the ground 



color yellow much suffused with fuscous 5 



— Smaller species, 1-2 mm. in length; thorax of male opaque black, 



generally with yellow lateral margins and faint indications of yel- 

 low marks between the vittas; thorax of female yellow with red- 

 dish or blackish vittae 6 



5. Third vein ending as far in front of wing-apex as upper branch of 



cubitus does behind it 4. infuscatus. 



— Third vein ending at less distance in front of wing-apex than upper 



branch of cubitus does behind it 5. striatus. 



*Trichocladius nitidus, described in this paper, has distinct pulvilli, and except 

 in having iinicolorous legs resembles Cricotopus closely. 

 tBull. 124 (1908), N. Y. State Mus., p. 282. 

 iEnt. News, Vol. 18, 1907, p. 400. 



