AMERICAN COLEOPTERA. 221 



So far as T know, these species are not found in salt marslies, but 

 frequent the borders of streams and ponds. 



Flanks of protliorax concave along the side margin 2. 



Flanks of protliorax convex ....8. arinatiis. 



2. — Under surface of protliorax with an impressed lino parallel with the 



margin 3. 



Under surface of prothorax without impressed line 9. cribi'i(*ollis. 



3.— Elj'tra densely punctured 10. ciispiditf iiM. 



Eh'tra sparsely punctured 11. poIitiiN. 



Elytra finely punctured; punctures and dorsal line of prothorax indis- 

 tinct.. 12. flavipeiiuis. 



8. B. ariiiatus, Er. Staph. 779; Oxyfelus arm., Say, Journ. Ac. Xat. So. 

 Phila. iii, 155; ed. Lee. ii, 100. — Dark chestnut-brown, sometimes blackish- 

 brown, somewhat shining. Head finely granulate, with an impressed line from 

 the frontal suture to the vertex. Antennae with the sixth and seventh joints 

 gradually larger. Mandibles with a strong tooth near the tip. Prothorax not 

 wider than long, front angles rounded, sides parallel, then rounded into the 

 base, without angles; disc coarsely and sparsely punctured, very finely granu- 

 late, dorsal line deep. Elj'tra convex, usually less dark, rather shining, deeply 

 rather densely punctured, sutural angle rounded. Dorsal segments feebly and 

 sparsely punctulate; ventral segments finely rather densely punctured. Side 

 margin of prothorax fine, but distinct, flanks not concave. Length 5 — 7.5 mm ; 

 .20— .25 inch. 



%. — Supra-antennal ridges strong and acute; anterior angles of epistoma 

 elevated into acute cusps; vertex with a tubercle which is divided by the 

 longitudinal line. 



9. — Supra-antennal ridges broader and smaller; epistomal cusps obsolete; 

 vertical tubercle very feeble. There are no differences in the last ventral 

 segments. 



Kansas, Arizona, Nevada, California. The specimens collected by 

 Say were evidently immature, since he describes the species as pale 

 reddish-brown with black head. 



9. B. cribricoIliM, n. sp. — Brown or blackish-brown, rather shining, au- 

 tennse ferruginous. Head scarcely perceptibly granulate, impressed line ex- 

 tending from the frontal suture to the vertex. Prothorax a little longer than 

 wide, front angles rounded, sides parallel, then rounded into the base, with- 

 out hind angles; surface nearly smooth, with deep coarse scattered punctures, 

 dorsal line deep. Elytra densely and finely punctured. Dorsal segments nearly 

 smooth, ventral finely and sjjarsely punctured. Margin of prothorax acute, 

 flanks deeply concave beneath, without line parallel to the margin. Mandibles 

 with a large tooth near the tip. Length. 4 mm; .15 inch. 



%. — Epistoma with the anterior angles elevated into obtuse cusps; supra- 

 antennal ridges acutely elevated ; front convexly elevated near the epistoma, 

 convexity divided by the longitudinal line. 



9- — Epistoma not cuspidate; supra-antennal ridges less elevated, frontal 

 convexity not apjiarcnt, ventral segments alike in both sexes. 



Sau Diejz;o, California; three specimens collected by 3Ir. G. R. 

 Crotch. 



thans. amek. ent. soc. vi. (30) October 1877. 



