154 MEMOIRS ON THE COLEOPTERA 



a preoccupied name in the sulcatum group, but his description 

 seems to show that the frontal sulci are not truly analogous to those 

 of sulcatum Lee. The type may be described as follows: 



Form moderately stout, rather strongly convex, shining, deep black, 

 without metallic lustre, the elytra indefinitely paler at apex and each 

 with an oblique external pale spot between apical third and fourth; 

 under surface black, the legs dark rufous; head rather small, two- 

 thirds as wide as the prothorax, with large but only moderately 

 prominent eyes, the parallel converging ridges at each side strongly 

 marked; antennae moderately slender and blackish, the basal joint 

 rufous, nearly four-fifths as long as the elytra, the medial joints 

 cylindric, slightly more than twice as long as wide; prothorax two- 

 fifths wider than long, equally wide at base and apex, widest barely 

 before the middle, where the sides are subprominently rounded, 

 sinuate and then subparallel basally; transverse impressions dis- 

 tinct, especially the posterior; foveae moderate, rather deep and sub- 

 linear, not close to the equally long and distinct carina; hind angles 

 right; elytra slightly more than one-half longer than wide, almost 

 one-half wider than the prothorax, gradually obtusely ogival pos- 

 teriorly, the parallel sides feebly arcuate, the humeri not sharply 

 rounded; striae moderate, subentire, feebly impressed suturad; punc- 

 tures moderate, somewhat close, traceable to behind the middle; 

 foveae before basal and near apical third. Length (cf 9 ) 2.9-3.5 

 mm.; width 1.15-1.35 mm. New York (Lake Champlain) and 

 Michigan (Marquette). Many specimens. [Ochthedromus trepidus 

 Lee.] sulcatum Lee. 



This is a peculiarly northern species and seems to be subject to 

 very little intraspecific variation, even in size. Judging by the 

 drawing given by Duval, the European Bemb. gilvipes Sturm, which 

 in the latest catalogue is placed in the quadrimaculatum group pre- 

 ceding, should be congeneric with sulcatum; the frontal sulci are 

 perfectly similar as depicted by Duval. Sulcatum, however, is 

 certainly not a Lopha, nor is it even remotely related to quadri- 

 maculatum. The subgenus Lopha, because of the peculiar basal 

 formation of the prothorax, should be one of the first to receive 

 full generic rank, if any such ratings be made in the future. 



I have not seen the type of Ochthedromus trepidus Lee., and follow 

 the synonymy given by Hayward ; it seems to have been separated 

 from sulcatus by LeConte, because of the extreme flatness of the 

 strial intervals. An analogous case is that noted previously in 

 this paper of Melomalus effetus, in its relationship with flebilis, 

 which I cannot pretend to settle definitely without more material. 



