106 president's address — SECTION D. 



S. and W. Victoria, and New South Wales. These birds 

 are distinguished by their habit of forming a large mound of 

 sand and vegetable material in which the eggs are laid and 

 incubated. The mallee-hen is found in Victoria in the dry 

 mallee scrubs in the western part of the Colony and not in 

 the south-east parts and hence it is not surprising to find it 

 absent from Tasmania, the physiographical features of which 

 are scarcely suited to its habits. 



Finally, with regard to birds, a note by Mr. A. J. 

 Campbell is worth quoting, as it bears upon a point which 

 will be referred to again in dealing with the mammalia. He 

 says, " it appeared to me that some of those species of birds 

 common to Australia and Tasmania were larger in the latter 

 country than in the former, notably the thrushes and some of 

 the honey-eaters. The eggs also give greater dimensions. 

 The only hypothesis I can advance for the difference is climatic 

 influence." 



Mammalia. 



In this group Tasmania presents to us a fauna which may 

 perhaps be best described as a condensation of most that is 

 most noteworthy in the Australasian region. We have in 

 Tasmania representatives of the three great mammalian 

 groups, the Prototheria, Metatheria and Eutheria. To a 

 biologist the interest of these three groups so far as Australia 

 is concerned is in the inverse ratio of their stage of develop- 

 ment and numerical proportions. 



(1.) The Eutheria are only represented in Tasmania by 

 two cosmopolitan groups, the Cheiroptera and the Rodentia. 

 Of the former but little is known. The following Rodentia 

 are recorded in Higgins' and Petterd's list of Tasmanian 

 vertebrata : — 



Mus tetragonurus, pachyurus, castaneus, velutinus, setifer, 



fuscipes, gi'iseo-ceruleus, leucopus, variabilis, simsoni. 

 Hydromys chrysogaster. 



(2.) Prototheria. — This group includes only two families 

 which are at the present time entirely confined to the 

 Australasian region. 



(a.) JEchidnidce. — In this family only two genera are 

 now recognised, of which Proechidna is confined to New 

 Guinea. The other (Echidna) is common to Australia 

 and Tasmania. It contains only one species, of which three 

 varieties or geographical races are recognized by Mr. Oldfield 

 Thomas. 



