rOLYNE3IAN REALM. 103 



Rana, the frog, has a single species on the peninsula of York (R. 

 Papua), but is more abundant in New Guinea. Tree-frogs (Hyla) 

 are numerous. A peculiarity distinguishing the continental ophidian 

 fauna is the great preponderance of venomous over non-venomous 

 serpents. The proportion of the former to the latter is in some 

 sections, as in South Australia, as six to one. Two-thirds of all 

 the species belong to , the family Elapidae, to which the American 

 coral-snakes and the Indian cobra also belong. One species of 

 crocodile is found in some of the Australian waters. 



The fish-fauna is very limited, less than forty species being 

 known from the entire realm. Two species of lung-flshes, the 

 " barramundas " (Ceratodus Forsteri and C. miolepis), inhabit the 

 waters of C^ueensland. The paucity of forms is, doubtless, in part 

 attributable to the limited number of fresh-water streams. 



THE POLYNESIAN EBALM. 



The scattered island groups of the Pacific Ocean are so deficient 

 in the faunal elements that distinguish the main zoogeographical 

 divisions of the earth that they may be said to constitute a region 

 framed more by negative than by positive characters. For this 

 reason they have by many naturalists been relegated to the rank of 

 a mere sub-region. Yet, when we compare the Polynesian fauna 

 with the faunas of the other recognised regions, it becomes not a 

 little diificult to determine just where it should be placed, although 

 there would seem to be hardly a question as to the preponderating 

 relationship being with the Australian fauna, with which it has 

 generally been united. The addition, however, of so enormous 

 an annex to a region which combines in its faunal elements such a 

 remarkable individuality, and with which, after all, there is not very 

 much in common, does not appear natural ; and the less so, when 

 we recognise the full importance of the characters derived by the 

 Polynesian tract from regions other than the Australian, and its 

 own special peculiarities. For these reasons it seems advisable to 

 consider the region as one apart by itself. 



Zoological Characters of the Polynesian Realm.— This tract 

 is at once distinguished from the Australian, as well as from all 

 others, by the abscence of all Mammalia excepting bats. Of these 

 last there are representatives of two families, the Oriental fruit- 



