38 COLEOPTERA OP NORTH AMERICA. 



distinct neck, front with two supra-orbital setce ; clypeus mode- 

 rately prolonged, a setigerous puncture each side. Eyes large, 

 moderately prominent, narrowly separated from the mouth be- 

 neath. Labrum transverse, feebly emarginate, margin sexsetose. 

 Mandibles arcuate, acute at tip, not prominent. Maxillue slender, 

 ciiiate and spinous within, the outer lobe slender and with two 

 equal joints, the palpi slender, the terminal joint elongate-oval 

 and acute. Mentum deeply emarginate, toothed (except in 

 Pionijcha), ligula moderately prominent, the tip bilobed or nar- 

 rowed and bisetose; paraglossse slender and acute, usually longer 

 than the ligula; palpi slender, last joint oval acute, the penulti- 

 mate bisetose in front. Thorax elongate, narrower than the 

 head, margin feeble, sides with a setigerous puncture near the 

 middle and at the hind angle. Body subpedunculate, scutellum 

 not prolonged between the elytra. Elytra oblong-oval, not mar- 

 gined at base, lateral margin distinct and entire, without internal 

 plica, apices rounded without sinuation, disk striate, third interval 

 with three indistinct dorsal punctures. Presternum slightly pro- 

 longed at tip. Mesosternum oblique, the epimera very narrow. 

 Metasternal epimera distinct ; posterior coxte contiguous. Legs 

 slender, middle and posterior tibiis slightly ciiiate externally, 

 the anterior emarginate, its spurs very small. Tarsi slender, the 

 first joint as long as the next two which are oval, the fourth 

 broad, deeply bilobed aud papillose beneath, claws simple, dentate 

 or pectinate. 



The tarsi are alike in the sexes. The males have one seta ou 

 each side of the apex of the last ventral segment, the females two. 



The tribe as here constituted contains not only the Ctenodacty- 

 lides of Lacordaire, but also his Trigonodactylides. 



This tribe is represented in our fauna by Leptutrachelus, which 

 occurs in the Atlantic region. 



Tribe XXIII.— ODACANTHINI. 



Antennae slender, free at base, first joint as long as the next 

 two, three basal joints glabrous. Head oval, more or less elon- 

 gate, prolonged behind the eyes and narrowed to a neck, two 

 supra-orbital setae, clypeus moderately prolonged, truncate, a 

 setigerous puncture on each side. Eyes large, moderately promi- 

 nent, sexsetose in front. Maxillae slender, ciiiate and spinous 

 within, outer lobe biarticulate with equal joints, palpi slender, 



