71 



as two rugate carinae running the whole length of the 

 propygidium. If this and the last-mentioned character were 

 insisted on as generic Isodon, as it now stands, would need 

 to be broken up into four genera, and still further division 

 would be necessary in it if the sexual characters of the tarsi 

 were taken into account. 



The number of transverse carinae on the posterior tibiae 

 would suggest itself as likely to be a character of generic 

 rank ; but, again, it falls short of more than specific value, 

 for in some genera (notably Pimelopus) species with posterior 

 tibiae transversely bicarinate are quite closely allied with 

 others in which those tibiae are only unicarinate. 



Even in the mouth organs there is similar uncertainty. 

 M. Lacordaire records variation in the number of teeth in 

 the external lobe of the maxillae in genus after genus ; in 

 all the genera in which I have dissected the mouth organs 

 of any considerable number of individuals I have found that 

 the number of teeth in the outer lobe of the maxillae varies 

 with the species. 



When all these difficulties in the way of classification 

 have been considered there seem to be but few characters left 

 from which a better result can be looked for, and I am 

 obliged to acknowledge that the best scheme I can suggest for 

 the arrangement of the Australian Dynastides is unsatisfac- 

 tory to the extent of failing to associate together, in some 

 cases, species that probably ought to stand near each other 

 in a natural arrangement, which, I believe, would be one 

 that should treat sexual characters as of at least secondary 

 importance. In the scheme that I propose to follow I have 

 excluded sexual characters as, for the present, unworkable ; 

 but in some instances have added, in the tabulation of char- 

 acters/ 3 ) some sexual peculiarities in brackets (especially where 

 they distinguish the female) that seem sufficiently marked and 

 constant to be useful. 



As already indicated, I think the Australian Dynastides 

 should be divided into two main aggregates, in the former 

 of which the hind margin of the posterior tibiae is fringed 

 with ciliae or (rarely) short spines, and is more or less widely 

 truncate on its lower face, while in the latter it is non- 

 ciliate and non-truncate. The former of these includes nearly 

 all the Australian genera. 



The former of these aggregates I propose to divide into 

 two secondary aggregates distinguished by the structure of the 

 clypeus, which is best observed from a point obliquely in 



(3) This tabulation was not with the papers ready tor 

 publication. — A. M. Lea. 



