COLEOPTERA. 511 



Q. Elytra covering the abdomen. 



p. 531 SCYDMyENID^E. 



QQ. Elytra not covering the entire 

 abdomen, p. 533. 



SCAPHIDIID^E. 



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. 



LAMPYRIDJE. 



RR. Abdomen with only six 

 ventral segments, p. 552. 



MALACHIID^E. 



QQ. 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 CORYLOPHIDJE. 



JJ. Tarsi three-jointed. 



K. Antennae slender, vertictflate, with longhair, 

 abdomen not prolonged, p. 533. 



TRICHOPTERYGIDjE. 



KK. Antennae short, not verticillate, abdomen 

 prolonged, p. 533 HYDROSCAPHID.*. 



II. Abdomen with only three ventral segments, 

 p. 533 



HH. Wings not fringed with hairs. 



