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B. The two or four anterior tibiae externally excised. 



a. The posterior tibia? likewise denticulato-pectinated. The body short, 

 much broader in front. 

 Genus II. — Platysthetus, Mann, cornutus, morsetans, nodifrons. 3. 



0. The posterior tibiae simple. The body elongate, sublinear. 



Genus III. — Oxytelus, Grav. carinatus, piceus, longicornis, sculptura- 

 tus, depressus, Americanus, nitidulus, pusillus, caelatus. 9. 

 ii. All the tibiae simple. 

 Genus IV. — Trogophl.s;us, Mann, corticinus. 1. 



Tribe IV. — Omalides (Depressa, Latr.). 



The antenna? inserted in front of the eyes, beneath an elevated and prominent 

 margin of the head. The labrum transverse entire. The palpi short, with dis- 

 tinct joints, the last minute, conico-acuminate. The head with a distinct neck. 

 The abdomen, in the living insect, flat ; the legs simple ; the tarsi pentamerous. 

 I. The last joint of the tarsi elongate ; the rest collectively generally equal. 



A. The four anterior tarsi dilated and spongy. 

 Genus I. — Phloeocharis, Mann. Subtilissima. 1. 

 b. All the tarsi simple. 



1. The penultimate joint of the maxillary palpi dilated, the terminal one 



small and subulated. 

 Genus II. T^enosoma, Mann, gracile, pusillum. 2. 



2. The terminal joint of the maxillary palpi conical and subacuminate. 

 *. Antennae thickened towards the extremity. 



a. The body short ; the thorax short, transverse, not narrower behind ; 



the elytra covering the major portion of the abdomen. 

 Genus III. — Omalium, Grav. boreale, consimile, rotundicolle, piceum, 

 assimile, inflatum, pygmaeum, sibiricum, quadrum, fimetarium, tectum, ranunculi, 

 lapponicum, ophthalmicum, sorbi, depressum. 16. 



b. The body oblong ; the thorax short, transverse, somewhat narrowed 



posteriorly ; the abdomen generally twice as long as the elytra. 

 Genus IV. — Anthobium, Mann, rivulare, caesum, oxyacantha?, exiguura, 

 pusillum, planum, viburni, florale, nigrum, Gyllenhalli, salicis, salicinum, brunne- 

 um, deplanatum, striatum. 15. 



/S. The antenna? filiform ; the body oblong ; the thorax, both before and 

 behind, narrowed and rounded. 

 Genus V. — Acidota, Kirby. rufa, cruentata, crenata. 3. 

 ii. The last joint of the tarsi either as long, or a little longer, than the 

 preceding. 



