The geographical distribution of animals, with a study of the relations ...

——chap, xiii.] THE AUSTRALIAN REGION. 397while a much smaller number are confined to the East andSouth-East, or to the North.Among the fresh-water turtles of the family Chelydida?there are three peculiar generaChelodina, Chelemys, and Elseya,all from Australia.Amphibia.—No tailed amphibians are known from the wholeregion, but no less than eleven of the families of tail-lessBatrachians(toads and frogs) are known to inhabit some part orother of it. A peculiar family (Xenorhinidse), consisting ofa single species, is found in New Guinea; the true toads(Bufonidae) are only represented by a single speciesof a peculiargenus in Australia, and by a Bufo in Celebes. Nine of thefamilies are represented in Australia itself, and the followinggenera are peculiar to it :Pseudophryne (Phryniscidse),Pachybatrachus,and Chelydobatrachus (Engystomydee) ; Helioporus(Alytidse) ; Pelodyras and Chirodyras (Pelodryadse) ; Notaden(Bufonidse).Fresh-water Fish.—There is only one peculiar family of freshwaterfishes in this region—the Gadopsidse—represented by asingle genus and species. The other species of Australia belongto the families Trachinidse, Atherinidse, Mugillidae, Siluridse,Homalopterse, Haplochitonidse, Galaxidae, Osteoglossidse, Symbranchidee,and Sirenoidei ; most of the genera being peculiar.The large and widely-distributed families, Cyprinodontidae andCyprinidse, are absent. The most remarkable fish is the recentlydiscovered Ceratodus, allied to the Lepidosiren of TropicalAmerica, and Protopterus of Tropical Africa, the three speciesconstituting the Sub-class Dipnoi, remains of which have beenfound fossil in the Triassic formation.Summary of Australian Vertebrata.—In order to completeour general sketch of Australian zoology, and to afford materialsfor comparison with other regions, we will here summarize thedistribution of Vertebrata in the entire Australian region, asgiven in detail in the tables at the end of this chapter. Whenan undoubted Oriental family or genus extends to Celebes onlywe do not count it as belonging to the Australian region, thatisland being so very anomalous and intermediate in character.