1909.] OF MARSUPIALS AXD MOXOTHEMES IX S.W. AUSTKALIA. 819 



the natural conditions. Rabbits, although already very iiumeious 

 in the Centre and )Soutli-East, have not yet found their way to 

 the Xorth-West. 



The mammals of the South-West, to about as far north as the 

 Moore River, have not disappeared in the same extraordinary 

 "svay, although they are rapidly retreating before civilisation, 

 being already very rare to the north of the thickly populated 

 distiicts around the >S\van River, as well as around all the settled- 

 in and agricultural areas. The burning of forests and general 

 clearing of the country, together with constant raids of dogs and 

 domestic cats, are among the chief causes. 



On account of isolation from enemies and disease, the abun- 

 dance of native mammals on the small islands oft" the coast, 

 compared in most instances with their scarcity, or in many cases 

 non-existence, on the adjoining mainland, is A^ery mai'ked, and 

 forms a key to the original distribution of many of them. Insular 

 foi'ms of South-Western mammals extend as far noi'th as the 

 Sharks Bay Islands in the West ; while in the tSouth sevei-al 

 occur on the islands oft" Esperance, reappearing again on the 

 mainland as well as on islands oft' the coast of South Australia . 



The mammals on the islands oft" )Shai'ks Bay correspond with 

 the originally widely spread " sand-plain fauna " of the Soutb- 

 West ; those on the islands farther south resembling the kinds 

 confined to the coastal and forest districts. On the islands to the 

 north of Bernier, the mammals seem to show a similar likeness 

 to those on the extreme northern mainland, while there would 

 seem to be absolutely no mammals peculiar to the Xorth-West, 

 those that do occur being stragglers from the South-West, North, 

 and Centre. 



Lagorchestes hirsutus Gld. (Text-fig. 256, p. 820.) 



Mainland form almost, if not entirely, extinct. Said j)ossibly 

 to still occur very sparingly on sand-plains to the east of Beverley 

 and York — where within quite recent times it was fairly plentiful. 



A single specimen was recorded from Hastings, near Kojonup, 

 in 1896,'" by the Perth Museum. 



Described as being very swift and to give a distinct sharp 

 whistle when put up, although I did not notice this on Bernier 

 Island. 



Whistler of Colonists. 



' Wurrup ' of natives (S.W.). 



Lagorchestes hirsutus berkieri Thos. (Text-fig. 256.) 



Plentiful on Bernier Island in heathy and spinifex country. 

 Unlike the other small Wallabies Lagorchestes is not gregarious, 

 frequenting more or less open country, where it lies up in a form 

 similar to that of a hare, which on Bernier Island is rather deep 

 and generally half hidden beneath a bush oi' tuft of spinifex, 



24 specimens collected. Bernier Island (south end). 

 Proc. Zool. Soc— 1909, No. LYI. 56 



