Casey — Observations on the Staphylinidae. 429 



tional and very singular specific character. The ongiceps, 

 of Fauvel, which by some mistake has found its way to our 

 lists, does not occur here; it is an aberrant species in hav- 

 ing the elytra sparsely setulose throughout, as above re- 

 marked, and I know of no American form to which it is at 

 all closely related. 



Subtribe Diochi. 



The chief characters distinguishing this subtribe are the 

 slender maxillary palpi, with the third joint elongate and but 

 feebly enlarged from base to apex and densely clothed with 

 minute recumbent pubescence in addition to the longer tactile 

 setae, the fourth joint being extremely small and slender, 

 aciculate and very oblique, the normal elytral suture and the 

 smaller, less transverse mentum. The antennae are of the 

 Xantholinid type, densely clothed with fine pubescence except 

 toward base, but are more slender than usual and are more 

 widely separated at base as in the Othii, with the epistoma 

 short, broad and trapezoidal between them. A character 

 which appears to be widely divergent from anything known 

 in the two preceding tribes, is the larger, less transverse, 

 broadly rounded and entire labrum, with a very minute median 

 denticle at the apical margin and the mandibles in Diochus are 

 arcuate, not grooved externally but with the outer edge 

 acute. The fine close-set punctures of the abdomen are also 

 different fix)m anything occurring elsewhere in the tribe, so 

 that, as a whole, Diochus is sufficiently isolated to demand 

 without doubt subtribal distinction. The single known genus 

 may be described as follows : — 



Body very small in size and slender, pointed before and betilnd or fusoid in 

 outline, the head very small, elongate, without frontal grooves or im- 

 pressions, evenly convex and unmodified on the flanks behind the rather 

 well developed and somewhat coarsely faceted eyes, the latter not sur- 

 rounded by a groove or impression; basal angles very broadly rounded; 

 gular sutures strong, straight, widely separated anteriorly, gradually 

 converging and becoming contiguous or nearly so at the extreme base 

 only; prothorax elongate, comparatively large, narrowed from the base 

 to the subcircularly rounded apex, the side margins acute to the apex; 

 neck narrow, abotit a fourth as wide as the head; prosternum tumid in 

 the middle posteriorly, the surface turned slightly upward anteriorly; 



