128 Proceedings of the Biologircd Societg of Washington. 
K. Upper surface more depressed, pronotum less 
convex, sometimes sunken in the middle be¬ 
hind callosities; scutellum not evenly and 
strongly convex, either low conv’^ex with 
median smooth line elevated, the scutellum 
therefore somewhat roof-shaped, or sometimes 
elevated at or near base, or with a Y-shaped 
elevated area. Ground color more grayish. 
G. bullatus Say. 
EK. Up)MU'surface more convex; pronotum rounded, 
sometimes sub-depressed; scutellum very con¬ 
vex, evenly rounded, median line usually 
scarcely elevated, or elevated Y-shaped area 
sometimes present. Ground color more yel¬ 
lowish. G. decoratus Uhler. 
DD. Scutellum about equilateral (subequilateral in G. 
atricolor Montandon), smoothl}* low convex, or 
almost i)lane; almost always unicolor. 
F. Head almost smooth, with a sharply im¬ 
pressed line running from near apex of 
tylus well up on vertex. 
G. scudderi Stal. 
FF. Head granular, impressed line w'hen present, 
broa'ter, less distinct and interrupted at 
base of tylus. 
G. iMedian smooth line of pronotum well 
defined, percurrent or nearly so, and 
slightly carinate. 
G. carinahis new' species. 
(JG. IMedian smooth lineof pronotum poorly 
defined, usually incomplete and not 
at all carinate. 
H. Form moreohlong, pronotum more 
elongate, scutellum narrow'er; 
piceous with a steely bluish glint, 
pale margins of hemelytra us¬ 
ually narrow or lacking. 
G. atricolor iMontandon. 
HH. Form more oval, pronotum more 
transverse, scutellum strictly 
equilateral; without steely blu¬ 
ish gliut, more or less broad 
margiiis of hemelytra pale. 
G. nliginosus Say. 
