Coleoptera. 35 



45. Fourth joint of tarsi extremely short, not visible from above; small beetles of 



rather bright colors. (NecrSbia, Phyllobamus, Pyticera) (PI. 7, fig. 133.) 



CORYNEimE 

 Fourth joint of tarsi not abnormally short ............................. 46 



46. Fifth segment of abdomen conically produced, as long as the three preceding 



ones; elytra not covering the abdomen completely. (Scaphidium, Baeo- 

 cera, ScaphisSma) .............................. , ..... SCAPfflDinXE 



Fifth abdominal segment not elongated nor conically produced ............ 47 



47. Trochanters attached to the internal margin of the femora. (TrichSdes, 



Clerus, Thanasimus) (PI. 7, fig. 132.) ....................... CLERID^ 



Trochanters interstitial, i. e. attached to the base of the femora. (Ptinus, 

 Mezium.) . ............................................... PTINID^ 



48. Antennae capitate, i. e. the last three joints forming an abrupt club; elytra 



truncate. (Sphaerites.) ............................... SPH^RITID^ 



Antennae simple, not clubbed ................................... . ..... 49 



49. Front coxae with a distinct side piece (trochantin). (See couplet 61.) 



Some MALACHI1DJE 

 Front coxae without trochantin; long, narrow beetles. (Lymexylon.) 



LYMEXYLONIDJE 



50. Front coxae flat, rounded or globular, small and not prominent ............ 51 



Front coxae conical, prominent, usually large .......................... .54 



51. Front coxae flat, elytra not longer than the prothorax, exposing five abdominal 



segments; small wingless beetles parasitic on beavers. (Platypsyllus.) 



PLATYPSYLLnXE 

 Front coxae rounded or globular; not such beetles ........................ 52 



52. Prosternum prolonged behind into a process which is received in a notch in 



the mesosternum; prothorax loosely attached to the mesothorax ........ 53 



Prosternum without such a backwardly directed process; eyes very small or 

 wanting; rare minute beetles living in the nests of rodents. (Leptinus.) 



LEPTINUXE 



53. Labrum fused with the front; antennae distant at base. (Cebrio, Scaptolenus.) 



Labrum free. (Plastocerus, Euthysanius.) ........... A very few Elateridae 



54. Abdomen with six ventral segments ................................... 55 



Abdomen with seven or eight ventral segments ......................... 63 



55. Fifth segment of abdomen conical, as long as the three preceding segments 



together, the sixth minute. (See couplet 46.) ........... SCAPHIDIID^ 



Fifth segment not conical nor excessively elongated ..................... 56 



56. Hind coxae flat, not prominent, covered by the femora in repose; first joint of 



posterior tarsi usually very short and indistinct ...................... 57 



Hind coxae prominent, at least internally ............................... 58. 



57. Tarsi with the fourth joint of normal size; pronotum continuous with the 



propleura (see couplet 46) .................................. CLEKJDM 



Tarsi with the fourth joint very small and indistinct; pronotum separated from 

 the flanks by a marginal line (see couplet 45) ........... CORYNETID^. 



