384 C. R. OSTEN SACKEN'S PRODROME 



a triangle in the middle, yellow ; an indistinct yellowish streak runs, on each side, from the 

 anterior margin of the segment, inside of the black, and does not reach the middle of the 

 segment ; the fifth and the following segments are black, with j'ellow hind margins ; 

 on the fifth the vestige of a triangle. Venter yellow ; blackish longitudinal lines on each 

 side of segments 2-4 ; the following segments black, with yellow margins. Legs ferrugi- 

 nous ; latter half of front tibiae and the front tarsi, black ; ends of the four posterior tarsi, 

 tips of hind femora and tibia), blackish. Wings : costal and first basal cells, the latter 

 except a small h^'aline square at its distal end, dark brown ; the proximal end of the 

 second basal cell contains a brown streak, not quite reaching the middle of the cell ; the 

 dark Ijrown crosslxand does not touch the hind margin, a small space at the end of the 

 fourth posterior cell being hyaline; the fifth posterior cell (except both its ends) and the 

 end of the anal cell, are also infuscated ; a faint In-own tinge spreads across the anal angle ; 

 the apical spot is coalescent with the crossband, marginal and first submarginal cells being 

 filled out with brown ; the second submarginal cell is encroached upon by a brown cloud on 

 its anterior half only ; a trace of a whitish halo on the distal margin of the crossljand. 



Hah. Two female specimens, the one from Cayuga Lake, N. Y. (J. H. Comstock), the 

 other from Montreal (Wm. Cooper), agree in all the above described characters. 



This species is very like C. jiudicus, monfamis, hilaris, etc., in its general apj^earance and 

 somewhat in the coloring of its abdomen ; but it is easily distinguished by the coloring of 

 its wings, as in all the above named species the first basal cell is nearly hyaline and the 

 first submarginal cell contains a hyaline space, separating the brown crossband from the 

 apical spot. Li C. siriaius the hyaline spot at the end of the first basal cell is much 

 smaller, the crossband stops short at the intercalary vein, the picture of the abdomen is 

 altogether different, etc. 



14. Chiysops frigidiis n. sp. 



? . The apical spot fills out the maiginal and iirst submarginal cells, ami invr.cles a portion of tlic second 

 sulnnarginal ; tlie crossband does not reach the posterior margin, but expands toward tiie anal angle ; basal 

 cells infuscated on their j)roximal lialf; face ^Lining black, with the usual stripes of yellow joUen ; abdomen 

 black, sides of the two basal segments yellow. 



Length, 7-8 mm. 



2 . The brown color in the bi'.sal cells occujiics more space; abdomen reddish-yellow, each segment with a 

 black spot in the middle; three last segments black. 



Female. Facial callosities black, shining, prolonged anteriorly and meeting alcove the 

 mouth ; between them a stripe of yellowish-gray pollen ; cheeks black, shining, separated 

 from the facial callosities by broader stripes of the same pollen. Front clothetl with grayish 

 pollen ; frontal callosity and space around the ocelli, black. Antennae black, the first two 

 joints more or less tinged with reddish ; first joint compai'ativcly stout. Thorax blackish, 

 clothed with yellowish hairs, esjiecially on the sides of the dorsum and on the pleura) ; a 

 broad median greenish-gray stripe, brownish in the middle, lateral greenish-gray stripes be- 

 tween the humeri and the scutellum ; a brown stripe between the humeri and the roots of 

 the wings; pleura) yellowish-gray, with yellow hairs and a blackish stripe in the middle. 

 Abdomen black, sides of the two first segments reddish, leaving on the second segment a 



