new Genus of Australian Beetles. 435 



Northern Australia. They evidently form a natural group, 

 which I propose to call 



Macropocopris, gen. nov. 



Corpus compactum. Caput et thorax inermes. Tarsorum omnium 

 articulus ultimus magnus, conicus. Ungues validi, fortiter flexi, 

 basi lobati. Scutellum invisibile. Cetera ut iu gene re Ontho- 

 phago. 



The characteristic claw-structure is very peculiar. The 

 claw-joint is enlarged and conical, with its broad end distal 

 and its lower edge produced in the form of a strong blunt 

 spine between the claws. The claw is very long and doubled 

 upon itself so that the basal part forms a strong lobe, sepa- 

 rated only by a narrow space from the reflexed terminal 

 part. A leaf-like scale sharply pointed at the end flanks each 

 claw externally. There is only a single pair of long terminal 

 setse at the upper edge of the claw-joint, and the pulvillus, 

 usually represented by a pair of seta? at the base of the claws 

 beneath, is absent. This arrangement evidently enables the 

 beetle to cling to the hair of the wallaby, which would be 

 impossible for Onthophagus, with its quite simple and gently 

 curved claws. 



In his synopsis of the Australian species of OntJiophagus 

 (Trans. Roy. Soc. S. Australia, xxvii. 1903, p. 265), Black- 

 burn has included two species of Macropocopris in his 

 Group IV., in which the pronotum is " pseudo-margined " 

 (viz., kingi, Har., and parvus, Blackb.), and three in 

 Group VI., in which it is without a basal margin (inermis, 

 Mac!., muticus, Macl., and submuticus, Blackb.), while O.car- 

 modensis, Blackb., subsequently described, falls into his 

 Group V. I believe his 0. muticus and submuticus to be 

 really identical with 0. kingi and parvus respectively, and 

 inermis, Macl., to be the female of the latter. The supposed 

 difference in the prothoracic margin is illusory. The pseudo- 

 margin is present in all, but is invisible when the pronotum 

 and elytra are in close contact, being overlapped by the base 

 of the elytra. 



Blackburn has remarked, in his revision of the Australian 

 Onthophagi just referred to, that he knew of no external 

 feature by which the sexes could be determined positively in 

 all cases. D'Orbigny, who devoted many years to the study 

 of the same vast genus, made the same confession. But a 

 careful examination of the shape of the last ventral segment 

 will enable this to be done without difficulty. In the female 

 this segment is of nearly equal breadth throughout, whilst in 



