nn BARBOUR: ZOOGEOGRAPHY. 



so to sjieak, support the peculiar ophidian Ogmodon vitianus Peters and several 

 species of the amphibian genus Cornufer, which are, of course, not found else- 

 where. 



The Solomon Islands concerning which we ha\'e data are San Cristoval, 

 Ugi, Guadalcanar, Treasury Island, Faro Island, and Howla, in the Shortland 

 group; and Florida Island, or Gela. Thus if will be seen that for some of the 

 islands not a single record is forthcoming. Boulenger (Proc. Zool. soc. London, 

 1888, p. 90) prepared a table of distribution giving the ranges within the group 

 of all the species which were known up to 1888; and added again to our knowl- 

 edge of this fauna by another paper (Proc. Zool. soc. London, 1890, p. 30-31, 

 pi. 2), which reported upon C. M. Woodford's second collection from Gela; Wood- 

 ford being the person to \\hom, next to Guppy, we owe our most considerable 

 zoological knowledge of the group. 



But few of the species found here are confined to a single island; and the 

 exception occurs in the ophidian genus Denisonia, each of the three known species 

 of which occurs on a single island. The genus evidently evolved by isolation, 

 when most of the Solomons were connected in one land mass, from some Pseude- 

 laps- or Pseudechis-like ancestor, perhaps Pseudelaps itself; and then the 

 species each became differentiated from among the individuals isolated on each 

 'sland when the group took on its present asi)ect. It is hardly worth while to 

 discuss the reptiles at greater length. Suffice it to say that Gekkos occur as in 

 the Bismarcks, with the exception of two peculiar species of Lepidodactylus, 

 both confined to Faro Island, so far as is now known; but it must be remembered 

 that this island is better known herpetologically than almost any other, and 

 undoubtedly many species which appear to have a limited or discontinuous 

 distribution within the group are in reality of general dispersal, did we but know. 

 The same Gonyocephalus, Varanus, and Crocodilus occur also as in the Bis- 

 marcks; while besides the usual wide-ranging scincids, four peculiar species 

 occur, some found on a single island, others occurring on several. Corucia 

 zehrata Gray is an autogenous genus found probably throughout the grouj). 



Among the snakes a single peculiar Typhlops, T. aluensis Blgr., is note- 

 worthy, as apparently occurring only on Alu in the Shortland group; while the 

 species of Enygrus, Dendrophis, and Boiga occur widely spread. The species 

 of Denisonia have been mentioned. 



It is amongst the amphibians that we find a truly remarkable state of 

 affairs: — four a.stonishing Ranas, no one of the species confined to a single 

 island, all peculiar to the group; concerning the development of one species, 



