June i 9 oo.] Casey : On North American Coleoptera. 93 



sexes, the sutures transverse, perfectly free and virtually straight 

 throughout. The elytra have sometimes — as in plemis — a smooth 

 callous discal spot near the apex of each, which may be homologous 

 with the smooth polished mirror-like sexual spots of the melyrid genus 

 Eurclxmis. Sexual differences in the form of the body are occasion- 

 ally very pronounced, the male being shorter and stouter than the 

 female, with relatively broader prothorax and shorter elytra. 



The species before me may be tentatively characterized in the fol- 

 lowing manner : — 



Lateral spicule of the prothorax situated at or near the middle of the length ; front 

 not constricted between the antennte ; species general in distribution 2 



Lateral spicule situated far behind the middle, the sides just posterior to them fre- 

 quently arcuately prominent ; front narrowed by the very large antennal foveas. 

 Pacific coast 3 2 



2 — Sides of the prothorax broadly and conspicuously angulate at about the middle, 

 the spicule at the apex thereby rendered more prominent and separated from the 

 truncature of the anterior angles by a pronounced sinus 3 



Sides of the prothorax in the form of a continuous and generally evenly arcuate curve, 

 from the truncature of the apical angles to the base, the submedian spicule ab- 

 ruptly projecting from the limb and frequently extremely small 15 



3 — Eyes large, generally one-half as long as the head or more ; elytra finely and rather 

 closely punctured 4 



Eyes smaller but more strongly convex, always much less than one-half as long as the 

 head 6 



4 — Nodes of the thoracic angles very prominent and posteriorly unciform, the pro- 

 thorax much wider anteriorly than at the middle, rather finely but deeply, 

 densely punctate, the discal callous spots obsolete ; elytra elongate, between three 

 and four times as long as the prothorax. Length 1. 9-2. 5 mm. ; width, 0.75-0.9 

 mm. Europe, Siberia and Northern America acutangulus Gyll. 



Nodes moderate in development, acute but' not unciform posteriorly, the prothorax 

 equally wide anteriorly and at the middle 5 



5 — Pubescence long, coarse and very conspicuous, the serial hairs of the elytra dis- 

 tinct ; elytra distinctly more than three times as long as the prothorax. Length 

 2.2-2 5 mm. ; width 0.9-1.0 mm. Europe and Northern America. 



cellar is Scop. 



Pubescence short and more decumbent, less coarse and very much less conspicuous, 

 the serial hairs subobsolete ; pronotum finely but deeply, only moderately densely 

 punctate, the callous spots feeble ; elytra more oval and less elongate, about three 

 times as long as the prothorax. Length 1. 9-2. 1 mm. ; width 0.8-0. 85 mm. 

 California debilis Lee. 



6— Elytral punctures fine, the pubescence very short, inconspicuous and decumbent, 

 the subserial hairs subobsolete or very short, the pronotal callous spots obsolete 

 or scarcely traceable ; nodes of the thoracic angles sharply truncated, the pro- 

 thorax as wide at the middle as at the apex 7 



