370 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



represented by a single species, and four peculiar genera of the family 

 Viverridce; of all Ruminants and Proboscidians; all Pachyderms ex- 

 cept a single African genus of Suidce; and all Eodents except a few 

 species of Muridce. The Insectivores are almost wholly represented by 

 one or two species of Crocidura, and a family, embracing several genera, 

 not found elsewhere, save a single genus in the West Indies. Four 

 families of Bats occur, but are represented, with one exception, each by 

 a single species. They belong to groups of semi-cosmopolitan range, 

 and owing also to the exceptional means of dispersal possessed by 

 the Chirnptera, have little weight in determining the affinities of the 

 fauna. The Quadrumanes are represented only by the Prosimice, of 

 which three-fourths of all the species occur here, while about four-fifths 

 of the remainder are African. The remains of an extinct species of 

 Hippopotamus have been found, a type existing at present only in Africa. 

 Although the Indian genus Viverricula has recently been established as 

 occurring in Madagascar, the few types that connect the Lemuriau 

 mammalian fauna with the fauua3 of other parts of the world are pre- 

 ponderatingly African. 



With the exception of the Bats, which, for reasons already given, are 

 scarcely entitled to consideration in the present connection, the mam- 

 malia of "Lemuria" are, generally speaking, the lowest existing repre- 

 sentatives of their respective orders. The most prominent type, em- 

 bracing, in tact, about three-fifths of all the species (excluding the half 

 dozen species of Ghiroptera), belong to the Prosimice, the lowest of the 

 Quadrumanes, which in early Tertiary times had representatives over 

 a large part of the northern hemisphere, and perhaps had at that time 

 a nearly cosmopolitan distribution. The Carnivores are likewise allied 

 to early types of the Viverridce, which formerly had a much wider range 

 than at present; and the Insectivores are also of low forms, and allied 

 to early types. These facts seem, at first sight, to lend support to the 

 hypothesis, first advanced by Dr. Sclater, that Madagascar and the Mas 

 carene Islands are but remnants of a former extensive land-area that 

 possibly had connection with America as well as India, and embraced 

 portions of Africa. The supposed former relationship with America is 

 indicated perhaps not so much by the presence of Solenodon in the West 

 Indies, and of American forms of Serpents, Lizards, and Insects in Ma- 

 dagascar, as by the abundant occurrence of Lemuroid remains in the 

 North American Eocene. Since, however, these early Lemuroid forms 

 appear not to have been true Lemurs, but a more generalized type, having 

 affinities also with the Carnivores and Insectivores, and since they occur- 

 red also in Europe, and probably in Asia (for recent palaeontological dis- 

 coveries in our American Tertiaries show that much may be expected 

 from future explorations elsewhere), it is possible that the explanation 

 of the present distribution of the Prosimice needs not the supposition of 

 the existence of any very extensive land-area that has since disappeared: 

 in other words, that the African and Madagascareue Lemuridce may 



