McCuLLOCH. — New Discoglossoid Frog from New Zealand. 449 



some interesting modifications in the development of this frog may occur, 

 such as is exhibited by the Australian Pseudophryne* of which the hatching 

 of the ova may be postponed for a period of at least three months when 

 dry conditions prevail. 



According to A. S. Thomson,! L. hochstetteri also hides under stones. 

 He found that it was so rare and of such retiring (perhaps nocturnal) 

 habits that even the Maoris w^ere not acquainted with it. Possibly this 

 habit of close concealment was engendered by escaping from the voracity 

 of the moas. 



The vertebrate fauna of New Zealand has always been regarded as one 

 of fascinating interest. At the first glance the poverty of reptiles and the 

 complete absence of mammals appear to indicate that New Zealand has 

 never held direct intercourse with any continent — that, in biological phrase. 

 New Zealand is " oceanic " rather than " continental." Such a conclu- 

 sion is, however, vigorously combated both by the fauna as a whole and 

 by the varied and well-developed flora. " No other country on the globe," 

 wrote Wallace, " has such an extraordinary set of birds." And returning 

 to the reptiles, though the , brief records enumerate no snakes and only 

 one frog and fourteen lizards, yet the presence of the Sphenodon alone 

 confers on the New Zealand fauna a distinction lacking in many with a 

 far longer roll-call. 



Thus the quality of the New Zealand reptilian fauna makes amends 

 for its quantity, and establishes the fact that land communication once 

 really did exist between it and the outside world. But the old fashion of 

 those few inhabitants implies that the date of such traffic was a remote 

 one. When large problems depend for their solution upon scanty data, 

 science is athirst for every drop of information, and so the discovery of 

 a second indigenous frog is of special interest. 



The discoglossoid frogs form a small, compact group remarkable for 

 their primitive structure and for a disconnected distribution, discordant 

 with usual faunistic associations. StejnegerJ considers that their original 

 home was to the south-east of the Himalayas, and that in early Cretaceous 

 times the discoglossoids radiated thence to New Zealand, to western 

 America, and to western Europe. But central Asia can have had no 

 relations or direct communication with New Zealand. As the mass of the 

 Australian Amphibia arrived there from Sovith America via Antarctica, 

 it is now suggested that, whether originally Asiatic or Neotropical, Liopelma 

 had a similar history. Together both the frog faunas of Australia and 

 of New Zealand might have arisen in South America, both escaped by a 

 southern outlet^ — the one to New Zealand, the other to Australia — and 

 by the eastern door of " Arch-helenis " both may have been admitted to 

 the Mediterranean region by way of north-west Africa, and thence to Asia. 

 But the difference between the Discoglossidae of New Zealand on the one 

 hand and the Australian Hylidae and Cystignathidae on the other would 

 then imply that the different migrations flowed at different periods and 

 perhaps by different channels to New Zealand and to Tasmania respectivelv. 



* J. J. Fletcher, Proc. Linn. Soc. N. S. Wales, vol. 2, p. 379, 1881». 



t A. S. Thomson, Edinburgh Netv Philos. Journal, vol. 55, pp. 06-69, 1853. 



X L. STB.JNEGER, Bidl. .Am. Geogr. Snr.. vol. 37. p. 9. 1905. 



15— Trans. 



