42 OHIO STATE ACADEMY OP SCIENCE. 



Different specimens of this species taken in the same local- 

 ity are quite constant, but there appears to be considerable vari- 

 ation in the amount of infuscation of the first basal cell when 

 specimens from different sections are compared. Specimens from 

 the southern part of its range seem to show the most hyaline in 

 this cell. 



Common in May and June in all parts of the state. The 

 females are often observed on horses and cattle. 



CHRYSOPS OBSOLETUS Wiedemann. 



Length 7-8 mm. Basal segments of antennae yellow, second and 

 third segments usually black although the second is sometimes yellowish; 

 face yellow, its lateral callosities black; thorax above with two medium 

 greenish gray stripes narrowly separated by brown, the hyaline triangle 

 of the wing crosses the second longitudinal vein and in most specimens 

 reaches the costa ; the apical spot is confined to the distal parts of the 

 marginal and first and second submarginal cells, the cross band nearly 

 fills out the fourth posterior cell leaving only an obsolete margin at 

 its apex. 



Female: Frontal callosity black, both basal cells hyaline; dorsally, 

 abdomen black with a yellow middorsal stripe on the first four segments; 

 variations occur in which an additional yellow stripe is present on either 

 side of the middorsal one, and in some specimens the first two segments 

 are narrowly yellow on the sides. 



Male : Several specimens of this sex have the first basal cell infus- 

 ■cated and the abdomen black above with the single middorsal yellow 

 stripe ; otherwise like the female. 



Habitat : Common all over Ohio. 



This is a common species in woods where the females are an 

 annoying pest. I have taken numbers of the males by sweeping 

 along the margins of artificial lakes. 



CHRYSOPS SACKENI n. Sp. 



Length 8-10 mm. Abdominal segments one to four yellow on the 

 sides j apical spot where it joins the cross band equal in width to the 

 marginal cell plus one-fourth of the first submarginal at the same place. 



Female: Frontal callosity yellowish on the disk, and black on the 

 m_argin; annulate portion of third atennal segment black, remainder of 

 antennae, face and palpi yellow; first basal cell infuscated at base for 

 about one-third its length, and at apex on the narrowed portion; second 

 basal cell with a much shorter infuscation at base and scarcely any at 

 apex; cross band abbreviated behind, the fourth posterior cell not filled 

 out with brown ; the cloud on the last section of the fifth vein spreads 

 practically across the anal cell and communicates with the cross band 

 across the base of the fifth posterior cell; dorsally, abdominal segments 

 three to six with distinct posterior yellow margins which expand into 

 prominent triangles in the middle ; second segment with a prominent 

 triangle but not margined behind ; none of the triangles reach the anterior 

 margins of their respective segments; ventrally, abdomen yellow with a 

 mid ventral row of black spots and on each side two narrow black stripes ; 

 dorsally, the black on the second segment is composed of two oblique 

 spots connate at the anterior third and attaining both margins. 



