694 REVISION OF THE AMYCTERIDES, iv., 



have crossed over into the Bassian subregion. The route followed 

 by these species seems to have been different from that followed 

 by the species found to the north of the Dividing Range, in the 

 Mallee-districts of Victoria. The species found in the Mallee- 

 country are almost all dififerent from those of Southern Victoria, 

 although both types are found in South Australia. The southern 

 forms have extended further into Tasmania. 



The distribution of the genus may, perhaps, be most clearly 

 indicated according to its component groups. 



Group i. is strongly represented in South Australia by a 

 majority of the species, extending, on the east, into the coastal 

 and mountain-districts of Victoria and Tasmania, although the 

 exact number of species found in Victoria is doubtful. In South 

 Australia, the group appears to have its headquarters to the 

 north of Spencer and St. Vincent Gulfs; further west, in Eyre's 

 Peninsula, it is represented by the dimidiatus-suhgvouip, of which 

 an isolated species occurs on the western seaboard of Western 

 Australia. In New South Wales, another subgroup, of which 

 S. carinatus is the only described species, extends along the 

 southern mountains as far north as Orange. 



Group ii. radiates from South Australia east into the Mallee- 

 districts of Victoria, north into Central Australia {convexus- 

 subgroup), and west into Western Australia. The majority of 

 the West Australian species belong to this group. 



Group iii. extends along the mountain-ridges of the Main 

 Dividing Range in New South Wales, from the borders of Vic- 

 toria into Queensland. Two other species, of somewhat dissimilar 

 habit to the other members of the group, are, however, found in 

 South Australia and Victoria, and one of them in Tasmania. 



Group iv. appears to be limited to New South Wales; its dis 

 tribution is rather along the tablelands and western slopes 

 beyond the Dividing Range. 



Group V. also belongs more properly to South Australia, ex- 

 tending thence into the adjoining parts of Victoria, and into 

 Riverina in New South Wales. S. queenslandicus appears to 

 belong to this group, which is further represented in the south- 

 west of Queensland (CunnamuUa) by an undescribed species. 



