278 THE CANADIAN ENTOMOLOGIST. 



Individuals of the two sexes are very unequally represented in the 

 various groups, for, in tiie first group, out of seventeen examples before 

 me there seems to be only one male, and in the second, having 

 abbreviated elytra, out of twelve examples there is but one female ; in the 

 third group, among five examples, three are males and two females. 

 There is little or no sexual difference in structure, size or general 

 appearance. 



Rhexius, Lee. 

 This genus, composed of smaller and more slender species, replaces 

 Oropus in the Atlantic regions of America, and has very much the same 

 general facies, differing profoundly, however, in the constricted and greatly 

 narrowed apex of the prothorax, elongate basal antennal joint and general 

 absence of discal elytral strise. The single lateral and subposterior 

 thoracic tooth of Oropus is replaced by three minute and equidistant 

 denticles along the arcuate part of each side. The sexual characters are 

 even feebler than in Oropus, there being no dorsal modifications, and the 

 last ventral is merely larger and more apically impressed in the male; there 

 is no sexual difference at all in bodily form or habitus. The species are 

 similarly closely allied among themselves, necessitating careful observa- 

 tion ; those in my collection may be defined as follows : 



Body with longer, erect and more conspicuous pubescence 2 



Body with shorter, sparser and less bristling pubescence 3 



2. Form rather convex, shining, subimpunctate, testaceous ; head trans- 

 verse, the eyes moderate, the tempora long and only just visibly con- 

 verging, the base broadly sinuate, the occiput impressed, with a long 

 carinule extending to before the middle, the large perforate nude fovese 

 widely separated, before the middle, not connected with the strong, 

 broad, transverse sulcus behind the apical margin, the later being thin 

 and acute ; basal joint of the antennae very thin, as long as the following 

 six joints, the club as long as the funicle, with the eleventh joint as 

 long as the preceding three ; prothorax transverse, as v/ide as the 

 head, the part behind the apical stricture three-fourths wider than 

 long, the surface convex, the three basal pits as usual, not connected 

 by a transverse sulcus, the median sulcus strong, linear and, as usual, 

 extending onto the apical lobe ; elytra slightly abbreviated, as long 

 as the head and prothorax and one-half wider, the sides rounded, 

 the humeri distinct, the juxta-humeral impression large and strong, 



