98 PROCEEDINGS OF THE NATIONAL MUSEUM vol.87 



22. Elytra with a longitudinal fold above side margin -.23 



Elytra without a fold above side margin Lathrobium 



A. Eyes very small, at fi times their length from base subgenus Abletobinm 



Eyes moderately small, at not over 4 times their length from base B 



B. Elytra conjointly wider than long subgenu.s Apteraliom 



Elytra not wider than long O 



C. Head slightly emargmate behind; less than 5 mm. long - D 



Head rounded or trancate behind; generally more than 5 mm. long F 



D. Gular sutures divergent posteriorly... - E 



Qular sutures parallel subgenus Lathrobioma 



E. Pronotum much longer than wide; elytral punctures not serial subgenus Lathrolepta 



Pronotum scarcely longer than wide; elytral punctures in series subgenus Lathrobiopsis 



r. Oular sutures divergent from front subgenus Deratopeaa 



Oular sutures most approximate along middle or posteriorly Q 



G. Neck about one-third as wide as bead subgenus Tetartopeai 



Neck about one-half as wide as head subgenus Lathrobium 



23. Integuments subglabrous, subimpunctate, and highly polished; 



labrum broadly rounded and deeply emarginate at middle __ 24 



Integuments moderately sparsely punctate; labrum bilobed — Lobrathium 



A. Head above with distinct ground sculpture throughout subgenus Platydomene 



Head above without ground sculpture except occasionally at sides B 



B. Gular sutures converging posteriorly subgenus Enlathrobiam 



Gular sutures most approximate at middle or anteriorly 



C. Gular sutures most approximate along middle subgenus Lobrathium 



Gular sutures diverging from before middle subgenus Pseudolathra 



24. Labrum strongly bidentate Acalophaena 



Labrum not dentate. _ Dacnochilus 



25. Neck one-fourth as wide as head, or more 26 



Neck one-fifth to one-eighth as wide as head 35 



26. Basal half of front tibia with a concavity lined with diagonal 



ctenidia, usually with an expansion along posterior edge of 



concavity and a corresponding anterior prominence on femur 27 



Basal half of front tibia often with a concavity but never more 

 than margined with a single row of setae, without strong prom- 

 inences on tibia or femur Lobochilus 



27. Antennae normal 28 



Antennae with first two segments larger, rest verticillate, slender, 



of equal thickness throughout Thinocharis 



A. Labrum bidentate at middle subgenus Sclocharia 



Labrum not dentate at middle B 



B. Gular sutures widely divergent posteriorly subgenus Scioeharella 



Gular sutures most approximate posteriorly or along middle subgenus Thinocharia 



28. Pronotum distinctly longer than wide; seventh abdominal stern- 



ite in male generally distinctly modified; punctures of head not 



distinctly umbilicate though not very fine 29 



Pronotum not or scarcely longer than wide; seventh abdominal 

 sternite of male rarely modified; punctures of head umbilicate 



or fine and dense 30 



Eyes entirely absent Micranopa 



Compound eyes normal Orus 



A. Labrum quadridentate _ . B 



Labrum at most indistinctly bidentate _ subgenus Leuconw 



B. Male characters involving fourth to eighth sternites subgenus Pycnoros 



Male characters involving only seventh and eighth sternites subgenus Orn« 



Head with few or many distinctly umbilicate punctures, surface 

 sometimes densely punctulate. _ 31 



29 



30 



