]46 Thomas G. Sloane: 



The Eyrean Sub- region. — This immense division lias generally a 

 hot, dry climate; in no part has it a winter that brings snow nor 

 even (except near Cape Leeuwin) decided dampness. There is 

 abundant evidence of the long-continued prevalence of these condi- 

 tions, with the result that the now dominant types of the fauna are 

 composed of comparatively few wide-ranging species; such species 

 being often found in isolated colonies, sometimes at great distances 

 from one another. Attention was drawn to this fact by Professors 

 Tate and Spencer in the Report of the Horn Expedition. Some of 

 the most distinctive wingless Carabidae of the Eyrean sub-region 

 range from the coastal districts of Western Australia to New South 

 Wales (such are Garenum elegans, C. scaritioides, Neocarerwm 

 elongatum, Parroa hoirittl). 



Doubtless there are several centres of distribution in the present 

 Eyrean sub-region (e.g., Flinders Range, MacDonnell Ranges, 

 ranges of South-western Australia). There has been a great deal of 

 immigration into it from the Torresian and Bassian sub-regions 

 The Carabidae of the Eyrean sub-region are not numerous, consider- 

 ing its great area ; the eastern parts have more genera and species 

 than the western parts, owing to the numerous Torresian and 

 Bassian forms which have invaded the eastern borders of the sub- 

 region. Characteristic groups are : — The tribe Cuneipectini (one 

 genus with two species), the group Carenides (tribe Scaritini), and 

 such genera as Gnathoxys, Parroa and Adotela (tribe Broscini), 

 Phorticosomus (tribe Harpalini), Helluarchus and HeUuapterus 

 (tribe Helluonini). 



I divided the Eyrean sub-region into five districts in 1905. 

 These were numbered on my map from 6 to 10. 



(6) The Riverina district is probably merely part of the eastern 

 marches of the Eyrean sub-region. It may be considered to take 

 in the whole of the basin of the River Darling, its western boundary 

 being the watershed between the Darling and Barcoo Rivers. Its 

 chief distinctive character is the prevalence of immigrant forms 

 from the Bassian and Torresian sub-regions. 



(7) The South Australian District.— This lias for its centre the 

 Mount Lofty and Flinders Ranges; probably it should include the 

 Victorian Mallee districts, and it may extend round the head of 

 Spencer's Gulf to take in Eyre's Peninsula. It lias two very 

 isolated genera of the tribe Pterostichini, viz.. Secatophus and 

 Teropha. 



(8) South-west Australia. — This district should be defined by the 

 rainfall line of twenty inches to correspond with Tate's Autuchtho- 

 nian Province. 



