experienced hide themselves more carefully and live to propagate the race. GEOGRAPHICAL DISTRIBUTION. There is a very ably written chapter on the geographical distribution of the Amphibia by Boulenger in the _Catalogue of Batrachia Gradientia_, pp. 104-118. He came to the important conclusion that the geographical distribution of the Amphibia agrees in general with that of the freshwater fishes. Günther's division into a Northern, Equatorial, and Southern zone is modified only in so far as the last two are combined into one, "Tasmania and Patagonia not differing in any point regarding their Frog Fauna from Australia and South America respectively." Boulenger recognises– I. The Northern zone–(1) Palaearctic, (2) North American, region. II. The Equatorial Southern zone. _A._ Firmisternia division = Cyprinoid division of Günther. 1. Indian region. 2. African region. _B._ Arcifera division = Acyprinoid division of Günther. 1. Tropical American region. 2. Australian region. In the chapter on geographical distribution in Bronn's _Thierreich, Vögel, Systematischer Theil_, p. 296 (1893), and in my _Classification of Vertebrata_ (1898), due attention had been paid to the Amphibia as well as to the other classes of Vertebrata. It will be seen in the following pages that my arrangement is well applicable to the Amphibia so far as fundamental principles are concerned. It cannot be sufficiently emphasised that any attempt to form the various faunas of the different classes of animals into one scheme must necessarily be a _petitio principii_. The time-honoured six zoo-geographical regions established by Sclater and Wallace represent fairly well the main continental divisions: North America, South America, Africa, Australia, and the large northern continental mass of the Old World, with India as a tropical appendix. There is no correlation and no subordination {70}in this scheme. Huxley's division (1868) into NOTOGAEA and ARCTOGAEA (see p. 74) is of fundamental importance. The next improvement was the combination of the Palaearctic and Nearctic "regions" into one, an advance originally due to Professor Newton, carried out by Heilprin (1887) as the Holarctic region. I have, in 1893, substituted for it the more appropriate term _Periarctic_, meaning the whole mass of land which lies around the indifferent Arctic zone. The want of further co-ordination and subordination required the combination of the African and Oriental or Indian countries into a _Palaeotropical region_ (1893); the Ethiopian or African and the Indian or Oriental regions of Sclater and Wallace thereby assuming their proper subordinate rank of subregions.