COLEOPTERA. 51 1 



Q. Elytra covering the abdomen. 



p. 531 SCYDM^ENID/E. 



QQ. Elytra not covering the entire 

 audomen. p. 533. 



SCAPHIDIIDiE. 



OO. Posterior coxae approximate. 

 P. Antennae gradually thickened, or 

 clavate ; posterior tarsi not wid- 

 ened, p. 529 Silphid^e. 



PP. Antennae setaceous, filiform, 

 serrate, pectinate, or flabellate, 

 rarely with three somewhat larger 

 terminal segments, in which case 

 the tarsi are widened. 

 Q. Anterior coxae long, with dis- 

 tinct trochantins. 

 R. Abdomen with seven or eight 

 ventral segments, p. 550. 



LAMPYRIDiE. 



RR. Abdomen with only six 

 ventral segments, p. 552. 



Malachiid^e. 

 QO. Anterior coxae without tro- 

 chantins. p. 553..Lymexylid^e. 

 GG. Hind tarsi either only three-jointed or four-jointed, 

 but apparently three-jointed, the third segment being 

 small and concealed in a notch at the end of the sec- 

 ond segment. (See also GGG.) 

 H. Wings fringed with long hairs. 



I. Abdomen with six or seven ventral segments. 



". Tarsi four-jointed, the third segment small and 

 concealed in a notch at the end of the second 



segment, p. 534 Corylophtd/e. 



JJ. Tarsi three jointed. 



K. Antennae slender, verticiilate, with long hair, 

 abdomen not prolonged, p. 533. 



Trichopterygid^e. 



KK. Antennae short, not verticillate, abdomen 



prolonged, p. 533 Hydroscaphid/e. 



II. Abdomen with only three ventral segments. 



p. 533 SPH/ERIIDiE. 



HH. Wings not fringed with hairs. 



