424 EEVISIOK OF THE AMYCTERIDES, V., 



M. gagates Pasc, {I.e., p. IS), and ^f. tibialis Sloane, (Trans. Roy. 

 Soc. S. Aust., 1893, p. 229); while I have recently named a third, 

 M. hercules, (Trans. R. Soc. IS. Aust., xxxix., p. 74, 1915). To 

 this number, I have now to add a fourtli species, M . rol.undicollis. 

 Geographical Distribution. — The species are all inhabitants of 

 the western half of the continent, stretching from west of Lake 

 Eyre in Central Australia to the seacoast of Western Australia; 

 the genus appears to be absent from the south-west corner. The 

 range of M. tibialis and M. hercules appears to be almost co- 

 extensive with that of the genus. M. gagates is known princi- 

 pally from the neighbourhood of Geraldton and the Murchison 

 River, though inland, at Cue, its place is taken by J/, tibialis; I 

 have also a specimen labelled Central Australia. M. rotundi- 

 collis occurs on the Ashburton and Gascoyne Rivers. 



Table of lSpeciei<. 



l(4).vSupiaorl)ital crests represented by a slight ridge. 



2(3). Anterior tibite not emarginate in the male M. gagatts Pasc. 



3(2). Anterior tibia; with a subapical emargination in the male 



M. tibialis SI. 



4(1). Supraorbital crests Ijidentate. 



o(6). Prothorax subquadrate, size large M. hercides Ferg. 



6(5).Prothorax rotundate, size comparatively small. ..J/, rotundicollis, n.sp. 



MOLOCHTUS GAGATES PaSC. 



Pascoe, Journ. Linn. Soc , xii., 1873, p.l8, PI. ii., fig. 9. 



A recent visit to the British Museum has enabled me to 

 examine the type, a female, of this species, and to confirm its 

 identity with the species so named in Australian collections It 

 is closely allied to J/, tibialis Sloane, but may be readily distin- 

 ,'uished by the shorter and stouter legs, the difference being 

 more marked in the male; this sex further differs from the male 

 of M. tibialis in lacking the subapical emargination of the front 

 tibiae. 



There are, in my collection, two forms, which I regard as 

 belonging to this species, differing in the elytral sculpture, one 

 form having the elytral tubercles distinctly larger than in the 

 other, which is the typical form. 



?3 



