COLEOPTERA. 509 



PP. Ventral segments free. 



Q. Prothorax loosely joined to the 



mesothorax; front coxal cavities 



entirely in the prosternum. p. 544. 



ELATERIDJE. 



QQ. Prothorax firmly joined to 

 the mesothorax ; front coxal cav- 

 ities closed behind by the meso- 

 sternum. p. 548. . .THROSCID^. 

 OO. Prosternum without a process re- 

 ceived by the mesosternum, although 

 it may be prolonged so as to meet 

 the mesosternum. 



P. Posterior coxae contiguous, p. 534. 

 PHALACRID^E. 



PP. Posterior coxae separated. 

 Q. Body very depressed; middle 

 coxal cavities not closed exter- 

 nally by a meeting of the meso- 

 sternum andmetasternum. p. 537. 

 CUCUJIDA:. 



QQ. Body more or less convex; 

 middle coxal cavities entirely sur- 

 rounded by the sterna. 

 R. Prosternum not prolonged 

 behind, p. 538. 



MYCETOPHAGID^E. 

 RR. Prosternum prolonged 

 meeting the mesosternum. 

 S. Anterior coxal cavities open 

 behind, p. 538. 



CRYPTOPHAGID^E, 

 SS. Anterior coxal cavities 

 closed behind, p. 536. 



EROTYLID/E. 



MM. Anterior coxae conical, and projecting 

 prominently from the coxal cavities. 

 N. Posterior coxae dilated into plates 

 partially protecting the femora, at least 

 at their bases. 



O. Antennae serrate or flabellate. 

 p. 544 RHIPICERID^:. 



