THE CANADIAN ENTOMOLOGIST. 269 



Form more slender, very much smaller in size, linear, testaceous 

 throughout ; head scarcely wider than long, formed nearly as in 

 insolens, finely, sparsely perferato-punctate but more remotely so 

 medially ; fovea? large, separated distinctly more than either from the 

 eye, the frontal sulcus and its laminate anterior wall similar ; 

 prothorax nearly similar in form and finely, sparsely, uniformly 

 perferato-punctate, with the lateral teeth small but distinct, very 

 much smaller than the head, the foveae all smaller and more feeble 

 than in any other species ; elytra shining and very minutely, sparsely 

 punctulate as usual, subelongate, distinctly wider than the head, 

 parallel, with feebly arcuate sides, the impression obsolete at basal 

 third ; abdomen nearly as in insolens. Male apparently with simple 

 characters, the seventh ventral as in ifisolejis but more r.arrowly and 

 parabolically rounded behind ; last dorsal rather tumid or strongly, 

 longitudinally convex along a transverse subapical line. Length, 



0.8 mm.; width, 0.2 mm. ( ^ ). Ohio (Cincinnati), Dury 



exilissifmc:^ n. sp. 



My only example oi exilissivms is in a very fragmentary condition, 

 so that it is difiicult to even measure it, and the male sexual characters are 

 for the most part concealed by the mounting ; it is one of the frailest 

 and most minute of the entire Pselaphidse. In glancing over the 

 Pselaphidse of my collection, it may be casually observed that the smallest 

 and most slender species are Thesiastes atratus, Bibloplectus ricficeps and 

 Dalmosella te?ucis, which are certainly to be numbered among the more 

 wonderful of the inhabitants of this planet. 



AciuiJH, Csy. 

 The following species of this genus may be advantageously described 

 at the present opportunity : 



Actiiim bicolor, n. sp. — Stout, convex, polished, subimpunctate, the 

 pubescence fine and inconspicuous, testaceous^ the elytra brighter though 

 clouded at base and apex, the head and abdomen black; head of the usual 

 form, the two pubescent fovese separated by nearly half the entire width, 

 the ambient sulcus very feeble ; antennae moderate, joints seven to ten 

 gradually wider, the latter nearly four times as wide as long, the eleventh 

 as long as the preceding five, elongate-ovoidal ; prothorax slightly wider 

 than long and distinctly wider than the head, impunctate, broadly rounded 

 at the sides anteriorly, moderately narrowed toward base, with the usual 



