69 



Lacordaire places three subtribes, only one of which 

 (Oryctides) is known as Australian, and he distinguishes that 

 subtribe from the other two by its presenting sexual char- 

 acters in the head and prothorax. That particular character, 

 so far as concerns Australian Dynastides known to me, need 

 not be discussed here, inasmuch as the subtribes without 

 sexual characters in either front tibiae or head or prothorax 

 are not known to occur in Australia, but its classificatory 

 value is certainly discounted by the extraordinary variability 

 of development in the sexual structure of the head and pro- 

 thorax within the limits of a genus or even of a species (some 

 males of Dasygnathus, for example, having head and pro- 

 notum very little, and others enormously, different from those 

 segments in the female). 



M. Lacordaire divides the Dynastides having sexual char- 

 acters in the front tibiae into two subtribes (distinguished 

 from each other by non-sexual characters), but as only one 

 of these (the "true Dynastides") is known, or likely to be 

 Australian, their differences need not be discussed in this 

 memoir. The following, then, is M. Lacordaire's arrangement 

 of the Dynastides so far as concerns those of his subtribes 

 known to be Australian : — 



A. Labial palpi inserted on the sides of 

 the mentum. 

 B. Front tibiae similar in the two sexes Oryctides 

 BB. Front tibiae sexually elongate in 



the males ... ... ... ... true Dynastides 



AA. Labial palpi inserted in the internal 



face of the mentum ... ... ... Phileurides 



The first of the above subtribes (Oryctides) includes in 

 Lacordaire's arrangement nearly all the Dynastid genera of 

 Australia, and is subdivided into four ' 'Groups" (all of them 

 Australian). Here for the first time the structure of the pos- 

 terior tibiae finds a place in the tabulations, three groups 

 being distinguished from the other group (true Oryctides) by 

 having those organs truncate and ciliate at their apex, though 

 for some unaccountable reason he places in the true Oryctides 

 Dasygnathus, which has posterior tibiae strongly ciliate. The 

 three groups with ciliate posterior tibiae are distinguished by 

 the presence of sexual characters in the antennae (Orycto- 

 morphides) and the feebly (Pentodontides) or strong (Pime- 

 lojndes) triangular form of the basal joint of the hind tarsi. 

 The antennal sexual character (though no doubt an extremely 

 important one) is, like other sexual characters, unsatisfac- 

 tory, at any rate for the present. As regards the distinction, 

 inter se, of the two Groups not having sexual characters in 

 the antennae by the more or less triangular form of the basal 

 joint of the hind tarsi there are too great differences in that 



