president's address. 23 



pelago. It is limited northward by Wallace's line or strait, which 

 separates Lombok from Bali and Celebes from Borneo, including 

 Papua or New Guinea and the Solomon Islands to the eastward, 

 and southward embraces Tasmania or Van Diemen's Land. It is 

 especially distinguished by its numerous marsupial mammals, and 

 by the almost complete restriction of the class to representatives of 

 that order, the rodents and the bats ; the Monotremes are also 

 characteristic of the realm, and entirely confined to it. The class 

 of birds likewise has a number of very characteristic types : chief 

 of these are Megapodid^e and Casuarids, but there are several 

 others — c. g., the Paradiseidse, Meliphagidse, Menuridee, and At- 

 richidae — that are almost equally peculiar. The reptiles and am- 

 phibians are perhaps less noteworthy, although they present some 

 interesting features of detail. The fresh-water fishes are, however, 

 especially remarkable ; while many of what maybe called marine 

 families are represented by fluviatile species, there are several that 

 are peculiar to it or only found elsewhere in South America. 

 Among the former is the family Ceratodontidse, which in former 

 geological epochs was extensively represented in other parts of the 

 world, but is now peculiar to Australia. Among the latter are the 

 families Percophididse, Haplochitonidae, Galaxiidte, Osteoglos- 

 sidte, and Symbranchidse. The articulates and mollusks also afford 

 a large number of characteristic forms. The primary subdivisions 

 of the realm are two. 



VIII. THE ORNITHOGi^AN REALM. 



The New Zealand sub-region of Mr. Wallace cannot be satisfac- 

 torily referred to the Australian or any other realm, and, although 

 its peculiar characters are not very salient, it should apparently be 

 isolated as a peculiar realm. The name Ornithogsea, proposed 

 nearly ten years ago, may be retained for it. In prehistoric times, 

 it was the abode of a number of gigantic struthiiform birds, which 

 have been referred to one or two peculiar families — the Dinornithidse 

 and Palapterygids — and a related family — the Apterygidse — is still 



