Staphylinidæ.
7
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having its apex feebly sinuato-truncate and its lateral limits marked by very obtusely rounded unthickened angulations. Length 2.4 mm.; width 0.6 mm. Rhode Island (Boston Neck). |
Distinguishable from affluens principally by the notably different sexual modification fo the sixth tergite of the male. Superficially, the species of this section of Atheta resemble each other very closely throughout.
| Atheta (Stethusa) sagax n. sp.—Smaller than any of the preceding and with relatively shorter prothorax and elytra, similar in coloration and sculpture; head rather more transverse, very much narrower than the prothorax, the large eyes similar, and, as usual, finely faceted and having a few stiff bristling setæ; antennæ rather less developed but of the same type, the last joint fully as long as the preceding tow, the latter each but little shorter than wide, prothorax nearly one-half wider than long, parallel and broadly rounded at the sides, evidently narrower than the elytra; the basal angles distinct as usual; elytra pale brownish-flavate, feebly clouded toward the scrutellum; the suture but little longer than the prothorax; abdomen blackish, faintly rufescent basally and at apex, the sixth tergite (♂) with the medial truncature not more posterior than the tips of the slender dentiform process at each side of the apex and separated therefrom by nearly its own width, its apex faintly sinuato-truncate and its subangulate ends rounded and not at all thickened. Length 2.2 mm.; width 0.58 mm. Virginia (Norfolk). |
Seperable from any of the preceding by its rather smaller head and prothorax and small size of the body, as well as by differences in the male sexual characters.
| Atheta (Stethusa) sororella n. sp.—More slender than any of the preceding species and rather smaller in size, similar in coloration and sculpture; head moderate, the eyes large, convex, extending almost to the base; antennæ well developed, the last joint as long as the two preceding; prothorax transverse, parallel, very much wider than the head and a little narrower than the elytra, the latter short and transverse, the suture is not longer than the prothorax; abdomen much narrower than the elytra, rather shining, sparsely punctuate as usual, the lateral margins scarcely at all elevated, the sixth tergite (♂) with the apical lobe not projecting beyond the lateral processes and very wide, subsinuate medially and with very widely rounded unthickened angles, separated from each slender lateral process by but little more than half of its own width. Length 2.5 mm.; width 0.56 mm. New York (Catskill Mts.). |
The slender form and broad, feebly defined lobe of the sixth male tergite will probably prove efficient determinative characters for this species.
| Atheta (Stethusa) subdebilis n. sp.—Moderately stout, small in size, colored as in the preceding species, the fine close sculpture also similar; head |
