CH. II] PECULIAR TYPES OF ANIMALS. 109 



forms not by any means either as to the family or the 

 genus to which they belong, which are confined to this 

 region, extending sometimes for a greater or less distance 

 into the Nearctic, are the Tapirs, which are represented 

 by several species, some of which were separated by the late 

 Mr Alston as a distinct genus Elasmognathus : the Jaguar 

 and the Puma among the Carnivora, the former being 

 confined to the region: the Opossums of the genus 

 Didelphys are found here and in the southern parts of 

 the Nearctic : the Skunk may be mentioned in the same 

 category as the last : Bassaris is a carnivorous animal 

 whose affinities, now known to be with the bear tribe, 

 were at one time unrecognised ; it also extends into the 

 warmer parts of North America. The number of peculiar 

 genera belonging to the region is very large. Four of the 

 peculiar Gralline families contain but a single genus 

 apiece and very few species between them; they are all 

 of them birds whose position in the system is much 

 disputed, owing no doubt to their being the impoverished 

 relics of groups of birds at one time more abundant. 

 Palamedea and Chaima are believed to be a relic of an 

 ancestral tribe of anatiform birds; Cariama is said by 

 some to present resemblances to the Secretary bird of 

 Africa and to have therefore some relations to the birds 

 of prey. Psophia and Aramus are more distinctly rails, 

 while Eurypyga again is a bird which is allied to the 

 New Caledonian Rhinochetus, and to the Madagascar 

 Mesites, and possibly represents the sole remaining Ame- 

 rican type of a nearly extinct order of birds once 

 universally distributed. Of Opisthocomus the same kind 



