COLEOPTERA. 507 



FF. Metasternum witliout an antecoxal piece. 

 G. Legs fitted for swimming. 



H. With only two eyes. p. 523 Dytiscid^e. 



HH. With four eyes, two above and two below, p. 



525 GyrinidvE. 



GG. Legs fitted for walking, p. 537 Rhyssodid^e. 



DD. Ventral part of the first segment of the abdomen visible 

 for its entire breadth. 



E. Antennae with a lamellate club (Fig. 74, 8, page 60). 

 F. Plates composing club of antennae not capable of close 

 apposition, and usually not flattened, p. 554. 



LUCANID^E. 



FF. Plates composing club of antennae capable of close 



apposition, and flattened, p. 556 SCARABiEiDyE. 



EE. Antennae either clubbed or not, but when clubbed not 



lamellate. 



F. Elytra short, leaving the greater part of the abdomen 

 exposed ; the suture between the elytra when closed 

 straight ; wings present, and when not in use folded 

 beneath the short elytra ; the dorsal part of the abdom- 

 inal segments entirely horny. 

 G. Abdomen flexible, and with seven or eight segments 



visible below, p. 532 STAPHYLlNiDiE. 



GG. Abdomen not flexible, and with only five or six 

 ventral segments visible, p. 531 Pselaphid^e. 



FF. Elytra usually long, covering the greater part of the 

 abdomen ; when short the wings are wanting, or if pres- 

 ent are not folded under the short elytra when at rest; 

 the dorsal part of the abdominal segments partly mem- 

 branous. 

 G. Hind tarsi five-jointed. 



H. Antennae elbowed, and clavate. 



I. Elytra truncate behind, leaving two segments of 

 the abdomen uncovered, p. 541 Hjsterid^e. 



II. Elytra entire, p. 553 PTiNiDiE. 



HH. Antennae rarely elbowed, and then not clavate. 



I. Maxillary palpi as long as or longer than the 

 antennae, p. 527 Hydrophilid^e. 



II. Maxillary palpi much shorter than the antennae. 

 J. Tarsal claws very large ; the first three abdom- 

 inal segments grown together on the ventral 

 side. p. 543 ParnidjE. 



