36 Key to Families of North American Insects. 



58. Hind coxae widely separated 59 



Hind coxae approximated or contiguous 60 



59. Eyes absent (see couplet 60) A few SILPHID^ 



Eyes present, coarsely granulated; small, more or less ovate, brown beetles. 



(Euconnus, Connophron.) SCYDM^NIDjE 



60. Tibial spurs large, antennae gradually thickened or clavate; hind tarsi slender, 



not widened. Carrion-beetles (Necrophorus, Sflpha, Ptomophagus) (PI. 6, 



fig. 109; PI. 7, figs. 136, 137. 139, UO) SILPHIDiE 



Tibial spurs small or indistinct 61 



61. Front coxae with a distinct side piece (trochantin); rather small, usually soft- 



bodied species. (Malachius, Collops) {MELYRIDM). . . MALACHIIDiE 

 Front coxae without trochantin 62 



62. Elytra shortened, exposing several of the abdominal segments; very small 



species. (Micromalthus.) MICROMALTHIDiE 



Elytra entire. (Lymexylon, Hyloccetus.) LYMEXYLONEDiE 



63. Middle co.xae distant; epipleurae wanting; elytra usually with a reticulate sculp- 



ture; no phosphorescent organs. (Calopteron, Eros.) LYCID^ 



Middle coxae in contact; epipleurae distinct; elytra not reticulate 64 



64. Episterna of metathorax sinuate on the inner side; head nearly or quite covered 



by the thorax; epipleurae usually wide at the base of the elytra; phosphor- 

 escent organs generally present. Fire-flies. (Lucidota, Ellychnia, Photinus, 



Photiiris, Phengodes.) {MALACODtRMID.E) LAMPYRTD.^ 



Episterna of metathorax not sinuate on inner side; head not at all covered 

 by the thorax; epipleurae narrow at the base; no phosphorescent organs. 

 (Chauliognathus, Podabrus, Telephorus.) TELEPHOIODiE 



65. Tarsi four-jointed, front ones three-jointed in the males of some INIyceto- 



phagidae 66 



Tarsi with three joints or less 76 



66. Wings fringed with long hairs 67 



Wings not fringed 68 



67. Hind coxae in contact, with plates at least partially covering the femora. 



(Clambus, Calyptomerus.) CLAMBIDiE 



Hind coxae distant, transverse, not laminate; third joint of tarsi small, concealed 

 in the bilobed second joint. (Corylophodes, Molamba.) (CORY- 

 LOPHID^.) ORTHOPERJD^ 



68. Ventral segments all free and movable 69 



Ventral segments one to foiu- firmly united, immovable 75 



69. First tarsal joint greatly dilated, overlapping the very minute second and 



third joints and a part of the long fourth joint; minute trojjical beetles 



(Adimerus) (PI. 7, fig. 163) ADIMERID^ 



First tarsal joint not thus dilated 70 



70. Front coxae transverse; minute fungus beetles (Cybocephalus) (see couplet 26). 



NITIDULID^, part 

 Front coxae not transverse 71 



