146 



Further Notes on Australian Coleoptera, with 



Descriptions of new Genera and Species. 



No. XL. 



By the Rev. Canon Blackburn, B.A. 



[Read October 4, 1910.] 



LAMELLICORNES. 



SERICOIDES. 



Heteronyx (continued). 



Group V. 



Here commences the second of the two main divisions in 

 which I have distributed the Heteronyces. With the excep- 

 tion of a very small number of species, its members agree in 

 the outline of the head (viewed obliquely from behind), con- 

 sisting of three convex curves, the middle one being the out- 

 line of the labrum, the summit of which usually overtops the 

 level of the clypeus. In the aberrant species the outline of 

 the labrum appears truncate or lightly concave, which is also 

 the case with the aberrant species of the first main division. 

 In the aberrant species of the first division, however, the sum- 

 mit of the labrum does not overtop the level of the clypeus, 

 while in those of the second main division the reverse is the 

 case. This, no doubt, appears to be a trivial character, 

 but I find that its adoption distributes the species affected by 

 it much more naturally than they would be if all these aberrant 

 species were placed in either one of the main divisions. The 

 aberrant species of the first main division are much more 

 numerous than those of the second. 



A character of considerable value for the distinguishing 

 of species in this Group and the remainder is to be found in 

 the degree of separation inter se of the three convexities that 

 form the "trilobed outline" of the front of the head. In some 

 species, the middle convexity (i.e., the labrum) from a certain 

 point of view is seen to be wholly free from the lateral con- 

 vexities, so that it springs from (on either side) the base of 

 a lateral convexity and the outline appears as trilobed in the 

 strict sense of the term. When that is the case I call the 

 trilobed outline "divided." In other species the outline does 

 not present that appearance from any point of view, but the 

 middle convexity appears as an arch springing on either side 



