yo MEMOIRS ON THE COLEOPTERA 



and more slender than in the preceding. Length I . I mm. ; width 0.55 

 mm. Virginia (Fort Monroe). One specimen angustus n. sp. 



The antennae in this genus are rather long and slender, the club 

 especially extended, being much more slender than in Olibrus, with 

 an elongate-oval terminal joint giving no suggestion of the pyriform 

 outline characterizing Olibrus. There is a raised, posteriorly an- 

 gulate plaque behind the middle acetabula, which is possibly an 

 extension of the mesosternum, though this is by no means probable, 

 and it may be of an entirely different nature; at any rate, there is 

 no indication of it in Olibrus. The space between the subsutural 

 stria and the suture is generally convex, especially behind, taking 

 the place of a sutural beading which is otherwise wanting; it is con- 

 tinued unbrokenly around the apical angles and thence in narrow, 

 abruptly elevated form along the sides, this part bearing, except 

 apically, a fine groove along the edge. The epipleura are very 

 deeply and steeply inflexed basally as usual in the family. 



In the male of pallidus, and probably quite generally throughout 

 this genus, the anterior tarsi have on the under surface close-set erect 

 hairs, the distal extremities of which seem to be expanded into 

 minute glistening disks; in pallidus these tarsi are not very thick 

 but in some species the dilatation becomes marked. I attributed 

 the slightly greater paleness of the elytra toward apex in the types 

 of pallidus to translucency in greater part, but additional more 

 mature specimens show that there is really a large apical pale area, 

 somewhat as in viduus and apicalis. 



Convergens is rather aberrant in having a transversely curved 

 scratch-like modification of the punctures On the elytral flanks, more 

 or less noticeable also in the pusillus section, but these scratch-like 

 punctures are never developed to the degree seen in Acylomus. 

 Another aberrant species is prudens, where as also to some degree 

 in the subalutaceus section and particularly angustus the apex of 

 the prosternal process is nearly as in Olibrus, being convexly de- 

 clivous and devoid of bristles. In all these species every other 

 character however is that of typical Stilbus. 



The definition of species in the pusillus section by the number of 

 bristles at the tip of the prosternal process, may appear to be some- 

 what precarious, but I find these setae to be rather constant in char- 

 acter; this criterion is in each case reinforced, however, by numerous 



