MONOTOMIDyE 97 



and several other characters. The species known to me at present 

 can best be defined in tabular form as follows : 



Prothorax large, wider than long; body less slender 2 



Prothorax smaller, subquadrate, never distinctly transverse; body very 

 slender 3 



2 Surface dark ferruginous and rather shining throughout, subdepressed, 

 the micro-reticulation of the upper surface very feeble, coarser and 

 more distinct on the elytra; hairs short, sparse and inconspicuous; 

 head much wider than long and distinctly narrower than the pro- 

 thorax, the surface evenly and feebly convex, rather finely and closely 

 punctate, the punctures elongate; eyes rather large, convex and 

 prominent; antennae very short, barely longer than the head, the 

 third joint barely as long as wide, the ninth but little wider than 

 the eighth, the club rounded; prothorax about a fifth wider than 

 long, widest slightly behind the apex, where the sides are slightly 

 more rounded; apex and base subequal; sides nearly even but with 

 a few serrules about the rounded hind angles; surface flattened 

 medially, the flat area defined by parallel lateral and a transverse 

 posterior line, the lateral lines not extending to the middle; punc- 

 tures moderate and sparse, largely wanting medially; scutellum about 

 as wide as long, cordiform; elytra one-half longer than wide, not (cf ) 

 or very little ( 9 ) wider than the prothorax, the striae not very fine 

 and rather closely punctate, the punctures very close-set and con- 

 fused on the flanks; pygidium slightly wider than long, broadly 

 parabolic, convex, closely and very coarsely puncate, the additional 

 segment (cf ) very small; abdomen coarsely punctate, the transverse 

 series of foveae even and regular, the fifth segment very coarsely, 

 subconfluently punctate, the first with a gradually attenuated tri- 

 angular post-coxal plaque at each side, extending almost to the apex 

 of the segment in the male. Length (cf 9 ) 1.5-1.8 mm.; width 

 0.42-0.58 mm. New York and Indiana. Not uncommon. [Rhi- 

 zophagus ephippiger Guer.j ephippigerum Guer. 



Surface more convex, similarly micro-reticulate and shining, similar in 

 color and pubescence; head large, transverse, rather closely punctate, 

 more finely and sparsely anteriorly, the lateral oblique impressions 

 distinct; eyes prominent, much smaller than in the preceding; an- 

 tennae nearly similar, though evidently longer than the head; pro- 

 thorax still more transverse, fully a third to two-fifths wider than 

 long, formed nearly as in the preceding, but not flattened and not 

 definitely impressed medially, the punctures elongate, close-set and 

 subconfluent laterally, irregularly and somewhat widely separated 

 medially, arcuately somewhat condensed near the base; scutellum 

 nearly similar, well developed; elytra about one-half longer than 

 wide, just visibly wider than the prothorax, the sides perceptibly 

 arcuate; striae not very coarse but deep, finely but strongly punctate, 

 the flanks not striate but with a few well separated and irregular 

 series of punctures; pygidium wider than long, feebly convex and 

 very coarsely, polygonally punctate, the terminal segment of the 

 T. L. Casey, Mem. Col. VII, Oct. 1916. 



