Biology of the IVIembracidae of the Cayuga Lake Basin 281 



prouotuni is strongly inflated to produce a rounded swelling. Be fore this 

 swelling the dorsum is constricted. 



The two species found in the basin may be separated as follows: 



a. Proaotum with three irregular oblique lines trilineatiis 



aa. Pronotum with single yellow line at lateral margin lateralis 



53. Xantlwlobus trilineaius Say (Plate xxix. 1) 



1824 Membracis trilineaius Say, Narr. Long's Exp. App., p. 300. 



1859 Say, Compl. Writ. ! :200. 



1886 Cyrtosia trilineata Prov., Petite Faune Can. 3:239. 



1890 Van Duzee, Psyche 5 : 389. 



1892 Marring, Ottawa Nat. 6:30. ' 



1894 Cyrtolobus trilineatus Godg., Cat. Memb. N. A., p. 432. 



1908 Cyrtolobus { Xantholobus) trilineatus Van Duzee, Stud. N. A. Rlemb., p. 96, pi. 2, 



fig. 23. 

 1913 Xantholobus triliiuatus Funkh., Horn. Wing Veins, figs. 45, 67. 

 1916 Xantholobus muticus Van Duzee, Cheek List Hem., p. 61, no. 1695. 



Common. Usually taken on oaks, on which it shows th(^ same general 

 habits as the species of the genus Cj^tolobus. Easily recognized by the 

 much swollen posterior pronotum. 



Technical description. — Varies considerably in size and color, and somewhat in shape 

 of posterior swelling; generally large, robust, pronotum much swollen behind middle; brown 

 with pale vittae bordered with black; posterior process not reaching tips of tegmina; tegmina 

 smoky hyaline. 



Head subtriangular, yellow, punctured and marked with brown, roughly sculptured; 

 base nearly straight; apical margin with clypeus rectangular; eyes prominent, round; ocelli 

 distinct, brown, about equidistant from each other and from the eyes; clypeus large, sutures 

 distinct, punctate with brown, a brown vertical band on each side, tip continuing inferior 

 margin of face. 



Pronotum brown with a pale fascia down center of metopidimn, another extending from 

 anterior base of dorsal svvelUng to lateral margin of pronotum, and a third at base of posterior 

 process; each of these fascia broad, pale, and bordered on each side with black; dorsal swelling 

 beginning well behind humeral angles, distinctly bilobed, compression between lobes pale; 

 posterior process short, .stout, extending about to bases of apical cells of tegmina; entire 

 pronotum coarsely and densely punctate, not pubescent. 



Tegmina smoky hyaline, bases black and punctate, veins dark at base and in middle. 

 Undersurface of head and thorax black; abdomen flavous. Legs ferruginous; claws fuscous. 



Length 7-8 mm.; width 3-4 mm. 



54. Xantholobus lateralis Van Duzee (Plate xxix, 2) 



1908 Cyrtolobus (Xantholobus) lateralis Van Duzee, Stud. N. A. Memb., p. 96. 



1916 Van Duzee, Check List Hem., p. 61, no. 1696. 



Very rare. \'an Duzee's unique type specimen, which is now in the 

 Cornell collection, was taken on June 30, 1891, and no specimens have 

 since been collected in the basin. The species is apparently common 



