132 DAVENPORT ACADEMY OF NATURAL SCIENCES. 



tions before the transverse nervures, a large circular light spot cover- 

 ing the tips of the outer claval nervures and a smaller one at the apex 

 of clavus. Ultimate ventral segment of female short, nearly truncate, 

 the corners rounding; male plates long and narrow; antennal discs 

 nearly circular. 



Occurs abundantly on willows over a very wide area. The adults 

 that hibernate are usually much darker than those of the summer 

 brood. In some sections these have a distinctly rufus cast. 



Specimens are at hand from Ontario, New York, Iowa and Colo- 

 rado. Van Duzee has records of its occurrence in Ottawa, Canada, 

 (Harrington), Ag. Coll. Mich. (G. C. Davis), Quebec (Provancher), Cal- 

 ifornia (Coquillett), Franconia, N. H. (Mrs. Slosson). An examina- 

 tion of two of the ty[)es of inierriiptus, through the kindness of Prof. 

 Gillette, showed no character by which they could be separated from 

 typical alternatus. 



Idiocerus verticis Say. 



Jassi/s verticis Siiy. Jour. Acad. Nat. Sci., Phila., VI., ji. 308, 1831. 



Bythoscopus verticis Uhlcr. Bull. U. S. Geo), and Geog. Sur\., III., [i. 

 465, 1877. 



Idiocerus verticis Van Duzce. P.syche, V'., p. 389, 1890; G. (Jv: B., Heniip. 

 Colo., !>. 80, 1895. 



Pale brownish fading to nearly white, except the black spots on 

 vertex and scutellum. F^lytra pale brownish, broadly interrupted with 

 light. Length, '+ 4.5 mm.; cf, 4.25 mm.; width, i.io mm. 



Face and ail below creamy or greenish yellow; ocelli and spots on 

 the disc black. Pronotum light, washed with brownish, a few oblique 

 dark spots on the anterior part of the disc; scutellum yellowish, basal 

 angles black, tip white. Elytra white, washed with i)ale brownish, 

 nervures brownish interrupted with white, inner sector with a single 

 long interruption before the transverse nervure, suture with a light 

 spot in the middle. Ultimate ventral segment of female short, trun- 

 cate; pygofers rather long and narrow, exceeded by the ovipositor, 

 male plate long and slender, antennge short, with a very large disc 

 which scarcely reaches the clypeus. 



Missouri (Say), Denver, Colo. (Uhler). 



Found at Ames, Iowa, on willows along with the preceding species, 

 which it most resembles. It is usually of a lighter color, often nearly 

 white. Its smaller size, lighter color, and shorter ovipositor in the 



