52 BARBOUR: ZOOGEOGRAPHY. 



fined, so far as we know, to New Guinea; the other genus is Emydura, two of the 

 five species of which occur in New Guinea and AustraUa, while three other 

 forms are strictly Papuan. Crocodilus porosus Schn. occurs widely spread over 

 the whole island. 



Among these ten species of chelonians, then, six are peculiar to the island, 

 two generically autogenous; while of the other four, only one ranges into Malayan 

 waters, and this same one is the only one that is not generically distinct from 

 those genera known to the Malayan regions. The affinities of the various forms 

 do not seem particularly Australian, inasmuch as Emydura is represented in 

 Australia by only two species, one of which is reported only from Queensland; 

 while on New Guinea we find five. There seems for this reason to be no object 

 in not calling this genus truly Papuan in contradistinction to those genera which 

 have obviously had their centre of dispersal in Australia, or perhaps even in 

 Queensland. 



It may be best in considering the lizards simply to run through the genera 

 one by one, and note the relationships of each. 



Gymnodactylus has three species which are also found upon other islands in 

 the group, while four species are peculiar to Papua. The genus itself may 

 perhaps be considered a Malayan one. Markedly strange is the occurrence of 

 Thecadactylus australis, a species described by Giinther ; the only other species, 

 which occurs in the West Indies, being T. rapicaudus (Houttuyn). The first 

 mentioned species, discovered on one of the islands of Torres Straits, may be, 

 but is probably not, an example of convergence; since with Devisia occurring 

 here also, as well as cystignathoids which have a very South American look, it 

 is hardly fair to propose this as a probable explanation for the occurrence. 



Of Hemidactylus, there are two species, probable of Malayan origin, both 

 occurring elsewhere. 



Peropus may well be considered as probably having a purely Papuan origin; 

 the genus contains two species which are restricted to Papua, and three which 

 are found elsewhere as well. 



A single wide-ranging Lepidodactylus is reported. 



Of Gekko, a Malayan genus, one autocthonous species is found, likewise 

 another species which ranges through the Moluccas and towards the Solomons, 

 without occurring on any of the Sunda Islands. Liasis, on the other hand, may 

 be considered Australian ; of this genus one Australian species occurs, and another 

 which is found only on New Guinea. 



Amongst the Agamidae we have only Gonyocephalus, with four species. 



