ALLEN ON GEOGRAPHICAL DISTRIBUTION OF MAMMALS. 371 



have reached their present homes by migration from the northward 

 (leaving a remnant in India), at a time when North America and Asia 

 formed a continuous land-area, just as there is good reason for believing 

 that the greater part of the present faunae of India, Southern Europe, 

 and Africa are a comparatively recent immigration from the northward ; 

 that Madagascar derived, at a comparatively early period, its existing 

 fauna from Africa, as Mr. Wallace believes to have been the fact; and, 

 finally, that at a time antedating the appearance of the present African 

 fauna, Madagascar was actually united to the African continent.* 

 America is now not only currently considered to be the "Old World" 

 geologically, but it seems probable, as has recently been suggested, t 

 that the Equine, Tapiroid, Ehinoceroid, Cameloid, Suilline, and Cervine 

 forms, the Prosimice, and possibly the Proboscidians, Marsupials, and 

 Edentates, were either first developed in America, or had their origin 

 there in early generalized forms, and have since spread to the more 

 recently formed continents of the eastern hemisphere. Many of them, 

 as well as other early, generalized types, are known to have had a nearly 

 contemporaneous existence during the early part of the Tertiary period 

 both in America and Europe. This certainly lends probability to Mr. 

 Wallace's hypothesis respecting the origin of the present Lemurian 

 fauna. 



The families and genera represented in " Lemuria", their faunal alli- 

 ances, and areas of chief distribution, are as follows : — 



Lemurid^. — Chiefly developed in Madagascar, but occurring in Tropical Africa, South- 

 ern India, and the Malay Archipelago. Represented by about twelve 

 genera and about fifty species, three-fifths of which are peculiar to Mada- 

 gascar, and three-fourths of the remainder to Africa. Genera: — Indris, 

 Propithecus, Lemur, RapaJemur, Microceius, Lepilemwr, Chirogaleus. 



DAUBENTONnD^. — Peculiar to Madagascar and represented by a single species — Daii- 

 bentonia (^^Chiromys) madagascariensis. 



CRypTOPROCTrD-E. — One species {Cryptoprocta fe)'Ox), found only in Madagascar. 



ViVERRiDJE. — Warmer parts of Asia, the Malayan Islands, and Africa. Represented 

 in Madagascar by several peculiar genera and the Indian genus Viverricula. 

 Genera : — Fossa, Galidia, Galidictis, Viverricula. Species of the African 

 genus Herpestes also reported. 



El'PLERiD^. — Peculiar to Madagascar, and embracing the single genus Euplei'es. 



SuiD^. — Eastern hemispbere generally. Represented in Madagascar by species of the 

 African genus Potamochcerus. 



HiPPOPOTAMiDiE. — African. Represented in Madagascar by the remains of a species 

 believed to have but recently become extinct. 



Pteropid^. — The tropics everywhere, except Tropical America. Represented in 

 Madagascar and the Mascarene Islands by two species of the Indian and 

 Australian genus Pteropus. 



Rhinolophidje. — Warmer parts of the eastern hemisphere. Represented in " Lemuria" 

 by species of Bhinolophus. 



* Geogr. Distr. Anim., vol. 1, p. 273; Nature, vol. xvi (Oct. 25, 1877), p. 548. 



tSee especially Prof. O. C. Marsh's address on "the Introduction and Succession of 

 Vertebrate Life in America ", delivered before the Nashville meeting of the American 

 Association for the Advancement of Science, Aug. 30, 1877. 



