354 KANSAS UNIVERSITY SCIENCE BULLETIN. 



25. Abdomen without distinct black spots 26 



Abdomen spotted 31 



20. Abdomen black, covered with long yellow pile, legs yellow, the tips 

 of the femora and tibiae, and all the tarsi except basal two-thirds 



of the hind metatarsi, brown bracteatnm 



Abdomen nearly bare 27 



27. Body gray or cinereous 28 



Body brown or black 29 



28. "Body gray with a milky white lustre, specially the pleura and 



pectus. Legs tawny, femora and tibi» with irregular piceous 

 bands, tarsi piceous. Length 2. .5 mm. Hudson Bay Ter." This 

 is a synonym of vittatum Zett., according to Mr. Coquillet (1898). 



decorum 

 Thorax fuscous or cinereous pollinose, humeri pallid, pleura pale 

 cinereous, scutellum pale at the tip; abdomen blackish; fore 

 coxje pale, middle and hind ones cinereous; femora pale at the 

 base, black at the tip, tibias black. Length 3 mm. Mexican 

 species cinereiini 



29. Abdomen somewhat shinning, yellowish gray or whitish at the sides, 



and yellow at the base; legs brown, tibiae and fore coxeb white, 

 tip of tibiae and all tarsi black. European species, also occurring 



in Greenland reptans 



Basal segments of abdomen opaque, distal four segments somewhat 

 shining black or brown. Two long hairs at the tip of the first 

 and third fore tarsal joints 30 



30. Legs reddish yellow, tarsi black, except proximal half of middle 



and hind metatarsi which are light yellow. Length 2 mm. (St. 

 Vincent Island.) This is a synonym of pulch.ruiii Phil., according 



to Hunter tarsale 



Legs black; base of tibia, first joint of middle and hind tarsi and 

 sometimes ba.se of femora yellow; extensor .surface of all the 

 tibi* more or less whitish. A widely distributed and variable 

 species venustum 



31. Length 1.5 mm. Front and middle femora and tibiae wholly yellow; 



hind ones, except apices, also yellow. (Colorado) grisemn 



Length 2.5 mm. Legs, brownish black, distal part of femora, base 

 of tibia, and greater part of metatarsi light yellow (California). 



argiis 



Some of the characters used in this table have been taken 

 from the key given in the United States Department of Agri- 

 culture, Division of Entomology, Bulletin 10, new series, 1898, 

 page 68, by Mr. Coquillet. In the table given above I have in- 

 cluded all the North American species. For the southwestern 

 and Mexican species it should, however, be used with caution, 

 as I did not have specimens of some of these. 



