484 REVISION OF THE AUSTRALIAN SPECIES OF BOLBOCERAS, 



wrote when I described it, — viz.^ that the two must be very 

 closely allied, but that unless Macleay was actually incorrect in 

 his description of the front tibiae they are distinct. I now 

 describe 18 new species, bringing the total number to 54. 



The Australian Bolbocerata are readily divisible into two main 

 c^roups, in one of which the hind tibiae have more than one trans- 

 verse (or obliquely transverse) carina on their external face above 

 the cariniform apex, while in the other group there is only one 

 such carina. Unfortunately I cannot find that this (in my 

 opinion by far the most satisfactory non-sexual) character is even 

 referred to in any of the hitherto published descriptions of the 

 insects in question, due no doubt to the fact that describers have 

 not had occasion to look for non-sexual characters. But it 

 follows that I am unable to apportion to either group with abso- 

 lute certainty any species except those which I am able myself 

 to examine. Nevertheless I am able to say that in no instance 

 have I found the tibial sculpture of the First Group in any species 

 not having a particular kind of sexual development (viz., 1 horn 

 on the head and 2 on the pronotum of the male) and that all the 

 species I have seen with that sexual development have the hind 

 tibife pluricarinate; and as I have examined one or more species 

 having sexual characters of each of the types of sexual form that 

 have been attributed to Australian Bolbocerata, I am not at all 

 likely to be wrong in assuming that the species not having male 

 characters as indicated above must be excluded from the Group 

 with multicarinate hind tibiae even though I have not been able 

 to verify the conclusion by examining specimens. 



The males and females of the First Group (with the hind tibiae 

 multicarinate) present such extreme differences inter se — indeed 

 have so little in common — that after long and careful efforts I 

 have completely failed to find non-sexual characters on which it 

 is possible to found a tabulation of the species, and therefore 1 

 have had to adopt the course of tabulating the males and females 

 separately. The males present some variation in the degree of 

 development of their sexual characters (in the few species of 

 which I have seen numerous examples). Nevertheless there are 



