i\ 



48 BARBOUR: ZOOGEOGRAPHY. 



part of Papua itself. It has been customary to mention together in the same 

 category both the Ke and the Aru Islands, and to consider them both as purely 

 Papuan groups. This, however, is not justifiable, for the differentiation between 

 them is very strongly marked indeed. 



In drawing up these notes on the Aru Islands, use has been made of the 

 same paper by Roux which was referred to under the Ke Islands. We may note, 

 however, that among the species which he records in this paper on page 212 

 "zum erstenmal fur die Aru-Inseln nachgewiesenen Arten" appears Chondro- 

 python viridis (Schlegel), which, as a matter of fact, was described by Schlegel 

 from specimens from the Aru Islands, so that this is really the type locality 

 for the species. 



Roux also fails to point out a very fundamental difference between the 

 fauna of the Ke and Aru groups. This is largely, to be sure, one of degree, 

 many Papuan species occurring in Aru which do not get to Ke, while the species 

 in Ke are also Papuan and found in Aru. The important point is that many of 

 the species reach beyond Ke into the Moluccas; so that the important break 

 in the fauna occurs between Ke and Aru, and not between these two groups and 

 the Moluccas, the connection between Papua and Aru evidently having con- 

 tinued for a very long time after the break just mentioned took place. 



It is hardly necessary to discuss the fauna here in detail. It is practically 

 that of New Guinea itself; and even the differences are unimportant, in view 

 of the fact that any of the species supposedly confined to Aru may possibly be 

 found at any time in the little-known regions of New Guinea lying across the 

 straits. 



Curiously enough Typhlops seems to be absent, as also Stegonotus cucullatus 

 (Dum. & Bibr.), which occurs upon Ke and New Guinea. It has probably 

 simply not yet been found here. Otherwise all the Papuan snakes occurring 

 in Ke are found here, with Matrix doriae Blgr., and Glyphodon Iristis Gthr. 

 added; while Roux found also Myron richardsonii Gray, which was previously 

 known only from northern Australia. 



The lizards number twenty-eight, of which two are peculiar — Spheno- 

 morphus aruanus (Roux) and S. rufus (Blgr.). Lialis burtonii Gray was one 

 of Roux's most interesting discoveries, emphasizing the extremely close Papuan 

 affinity; while on the other hand the occurrence of Gekko monarchus (Dum. & 

 Bibr.) is unique, in that the species is derived from the west. This Gekko is a 

 rare species throughout its range, and one which would seem very unlikely to 

 be carried so far accidentally; if such a fate is not wholly improbable, at least 



