ALLEN ON GEOGRAPHICAL DISTRIBUTION OF MAMMALS. 365 



American affinities. Judged by other classes of animals, the fauna of 

 New Zealand is Australian (or Australian and Polynesian), but is yet so 

 specialized that the New Zealand islands must be recognized as forming 

 a distinct and highly differentiated region (New Zealand Region) of the 

 Australian Realm. 



As regards mammalia (and the same is true of the fauna and flora 

 considered collectively), Tasmania, Australia, and New Guinea have 

 many features in common, fully one-half of the genera (seven out of 

 fourteen) of mammals occurring in Tasmania being represented not only 

 throughout the greater part of Australia, but also in New Guinea. 



Tasmania and New Guinea are less rich in mammalia than Australia, 

 but this is obviously due to their insular character and small area. Tas- 

 mania is scarcely more closely related to Southern Australia than New 

 Guinea is to Northern Australia. Formerly, New Guinea was thought 

 to be very distinct from Australia, but the recent exploration of the 

 interior of New Guinea by MM. Beccari, d'Albertis, and Laglaize, has 

 brought to light the existence there of many forms before supposed to be 

 lestricted to Australia and Tasmania. M. Alphonse Milne-Edwards, 

 in a recent communication to the French Academy respecting some new 

 species of mammalia discovered in New Guinea by M. Laglaize, in refer- 

 ring to the close relationship existing between the fauna3 of New Guinea 

 and Australia, thus observes : " Plus on 6tudie la faune de la Nouvelle- 

 Guine'e, plus on lui trouve de ressemblauce avec celle de PAustralie, et les 

 indications fournies par la repartition des esp&ces animates permet d'affir- 

 uier qu'autrefois ces terres ne formaient qu'un seul grand continent. 

 Deja les resultats des voyages de circumnavigation entrepris dans la 

 premiere moiti^ de ce siecle . . . avaient permin de sour^onner 

 cette conformite d'origine ; mais elle a 6t6 priucipalement mise en lumiere 

 a la suite des explorations de M. Wallace, de M. Beccari et de M. d'Al- 

 bertis. Bnfin les collections qui M. Laglaize a formees dans ces regions, 

 ainsi que celles qui lui out ete remises par M. Bruijn et qui viennent d'ar- 

 river en France, fournissent des faits nouveaux qui accentuent encore 

 les ressemblances entrevues."* 



Formerly the Monotremes were supposed to be restricted to the south- 

 ern half of Australia and Tasmania, but within the last two or three 

 years the existence of Tachyglossus in North Australia (latitude 21) has 

 been established, and an allied species has been discovered in the mount- 

 ains of New Guinea. M. A. Milne Edwards has also just described a 

 species of Dromicia from New Guinea, and also a species of Hapalotis, 

 and Dr. Peters has recently added species of Phalangista, Chcetocercus, 

 and Hydromys, making six genera recently discovered in New Guinea 

 that were previously known only from Australia and Tasmania. 



So far as at present known, only three or four genera ( Uromys, Den- 

 drolagus, Dorcopis, and Mycectis) of mammals are peculiar to New Guinea 

 and the small islands situated between New Guinea and Australia, and 

 *Compte-rendu, torn. Ixxxv, 1079, cl6c. 3, 1877. 



