308 MEMOIRS ON THE COLEOPTERA 



The following is allied to quadrimaculatus Newm.; it represents 

 a type differing greatly from the three preceding species in facies 

 and sculpture, and, together with nobilis and quadrimaculatus, 

 is probably subgenerically different: 



Heterachthes fluviatilis n. sp. Slender, depressed, parallel, pale tes- 

 taceous throughout, subglabroue, the elytra with a few sparse punctures 

 bearing very short stiff erect fulvous setae; head but little darker, strongly, 

 rugosely sculptured, the eyes more widely separated than in ebenus; 

 antennae (cf ) as in quadrimaculatus in general form but with the third 

 joint materially shorter and the fourth longer, the fourth being fully 

 three-fourths as long as the third, while in that species it is only about 

 three-fifths as long as the third; prothorax similarly smooth but shorter, 

 only a little longer than wide, similarly biconstricted and with the apex 

 even more obviously wider than the base, smooth and almost impunctate; 

 scutellum very small; elytra rectilinearly parallel to the tips, three times 

 as long as wide, only about a fifth wider than the apex of the prothorax, 

 the apices evenly rounding to the sutural angles, which are right and 

 rather blunt; surface of each having an oblique oval flavous anterior 

 spot as in quadrimaculatus and another, very small and faint, near 

 posterior third. Length (cf) 7.3 mm.; width 1.4 mm. Missouri. 



Differs from quadrimaculatus in its narrower, more rectilinear 

 and more depressed elytra, which round to the apices much more 

 abruptly and posteriorly, in the much greater longitudinal distance 

 between the elytral spots, which are more unequal in size and 

 distinctly in antennal structure. 



The very small scutellum, radically different sculpture and 

 biconstricted prothorax are the principal generic characters sepa- 

 rating these species from those of the ebenus type. 



Malthophia n. gen. 



Body very slender, punctate and uniformly briefly pubescent; 

 head wider than the prothorax, vertical in front, the eyes coarsely 

 faceted and very large, completely contiguous above, separated by 

 rather more than a fourth the entire width beneath, deeply emar- 

 ginate, bordering the antennal tubercles, which are large, prominent 

 and very approximate, the anterior margin of the eyes slightly 

 sinuate beneath near the mandibles, the latter small, stout, smooth, 

 with a depressed pubescent external patch on each; palpi unequal, 

 slender, the last joint acuminate, with the tip narrowly truncate; 

 antennae much longer than the body in the male, very finely filiform 

 and simple, the basal joint short, stouter than the others, sub- 



