MAMMALIA. 



pacas (Ccdogenys), etc , etc., several of them belonging to families which are 

 confined to this realm. Here also the Marsupial opossums (Didelp^yida 1 ) 

 attain their maximum development, only a couple of species ranging into 

 North America ; while the camel-like llamas (Lama) are restricted to this 

 realm. The peccaries (Dicotyles\ again, are mainly South and Central American 

 while among the Carnivora the coatis (Nasua) are exclusively so. In addi- 

 tion to the llamas and peccaries, the only other Ungulates are deer, mostly 

 belonging to the American genus Cariacus. True deer (Cervus) are totally 

 wanting, as are all Insectivora. 



Here, it must be mentioned, that during the Pleistocene Period, or latest 

 division of the Tertiary Epoch, South America was populated by a much 

 more wonderful fauna. Among these were horses and mastodons (allies of 

 the elephants), together with a giant Ungulate (Toxodon) typifying a distinct 

 sub-order (Toxodontia) by itself, together with a second, known as the 

 Macrauchenia, which is likewise the type of a sub-order (Litopterna.) Here 

 also flourished the gigantic Glyptodonts, which are extinct allies of the 

 armadillos of the present day. Deer, llamas, peccaries, coatis, and various 

 cats were also present at the period in question. When, however, we go 

 back to a still earlier era the Lower Miocene horses, peccaries, deer, llamas, 

 coatis, and cats were entirely absent ; and the fauna consisted solely of 

 monkeys, marmosets, various peculiar extinct groups of Ungulates, arid 

 Hystricomorphous Rodents, together with certain peculiar extinct Mar- 

 supials, and some other groups which need not be mentioned. When 

 this fauna flourished, Neogsea must have been quite isolated from the rest 

 of the world. It is, however, clear that (although the Edentates may have 

 originated there) the Ungulates and Hystricomorphous Rodents must have en- 

 tered from other regions, although how they got there is at present a mystery, 

 seeing that none of the latter occur in the earlier Tertiary strata of North 

 America. At the close of the Miocene Period, South America became con- 

 nected with North America, from whence it received its extinct horses, to- 

 gether with its existing deer, llamas, peccaries, mice, coatis, cats, dogs, etc. ; 

 while, at the same time, a certain number of essentially Neogseic types obtained 

 a footing in North America. 



Although fuller details would be necessary to make this very complicated 

 subject clear, it is thus evident that previous to its latest and existing union 

 with North America, Notogsea possessed a very peculiar and characteristic fauna 

 which entitles it to form a primary realm by itself ; but that this original 

 distinction has been greatly obscured by later emigrations and immigrations. 

 Of this primitive fauna the Edentates, monkeys, marmosets, Hystricomorphous 

 Rodents, and certain Marsupials, are now remnants ; while the coatis and 

 llamas, which are at the present day confined to the realm, do not properly 

 belong to it at all. 



Arctogsea includes the whole of the rest of the world, and may be char- 

 acterised by the absence of Monotremes, Diprotodont Marsupials, and 

 Edentates, 1 and the presence of Insectivora ; Marsupials occurring only in 

 North America. This vast tract may be divided into a number of regions. 

 First and most distinct comes the Malagasy region, including Madagascar 

 and the Comoro Islands, which is specially characterised by the abundance of 

 its lemurs, civet-like Carnivores, and Insectivora, coupled with the absence of 



1 The pangolins and aard-varks are here separated as a distinct order (Effodientia), 

 The few Edentates straggling into North America may be disregarded. 



