454 FAMILY XV. — TINGIDID^. 



The genus is a large one, about 50 species now being known 

 from North America, 24 of which occur in the eastern states. 

 Of them Prof. Comstock has written : "Dainty as fairy brides 

 are these tiny lace-draped insects. One glance at the fine 

 white meshes that cover the wings and spined thorax is suf- 

 ficient to distinguish them from all other insects, for these 

 are the only ones that are clothed from head to foot in a fine 

 white Brussels net." For convenience our species are sepa- 

 rated into three groups. 



KEY TO GROUPS OF EASTERN SPECIES OF CORYTHUCA. 



a. Crest of hood much elevated, nearly or quite three times as high 

 as median carina of pronotum (figs. 100, a and b, and 102, 6). 



Group A, p. 454. 



aa. Crest of hood lower, never more than twice as high as median 



carina (fig. 102, d) . 



b. Costal area of elytra without a conspicuous brown basal and apical 



cross-bar. Group B, p. 458. 



66. Costal area with a well marked basal cross-bar and usually also 



with an apical one. Group C, p. 460. 



Group A. — CORYTHUCA. 



This group comprises eight rather large eastern species all 

 having the hood more than twice as high as the front part of 

 median pronotal carina. 



KEY TO EASTERN SPECIES OF GROUP A, CORYTHUCA. 



a. Entire side margins of both paranota and elytra dark brown; front 

 of head, viewed from the side, almost vertical. 405. bulbosa. 



aa. Costal area of elytra with a more or less evident basal and apical 

 cross-bar, the space between these usually in great part pale; 

 front of hood declivent. 

 6. Costal margins of elytra distinctly broadly concave; paranota with- 

 out spots; cells of hood very large; marginal spines long. 



406. CORYLI. 



66. Costal margins of elytra straight or nearly so. 



c. Outer half of paranota with a large dark brown spot or stripe; 

 hind margin of apical band of elytra straight. 407. cydoni^e. 

 cc. Outer half of paranota with small brown spots or none; hind 

 margins of apical band of elytra rounded or irregular. 

 d. Larger, length 3.5 or more mm. 

 e. Hood very large, subspherical, as wide or wider than high; 

 length 4 or more mm. 408. associata. 



ee. Hood smaller, usually less spherical, distinctly higher than 

 wide; length less than 4 mm. 

 /. Areolae of hood and paranota opaque, creamy white; length 

 3.5 mm. 409. elegans. 



