Coleoptera. 35 



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



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



CORYNETIDiE 

 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, Scaphisoma) SCAPHIDilDiE 



Fifth abdominal segment not elongated nor conically produced 47 



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



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



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

 Mezium.) PTINID.^ 



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



truncate. (Sphaerites.) SPILERITIDjE 



Antennae simple, not clubbed 49 



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



Some MALACHIID^ 

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



LYMEXYLONID^ 



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.) 



PLATYPSYLLIDiE 

 Front coxae rounded or globular; not such beetles 52 



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



the mesosternura; prothorax loosely attached to the mesothorax 53 



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

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



LEPTINID.^ 



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



CEBRIONID^ 

 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.) SCAPHIDnDjE 



Fifth segment not conical nor excessively elongated 5Q 



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) CLERID.^ 



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

 the flanks by a marginal line (see couplet 45) CORYNETIDiE 



y 



