Zoological Society. 305 



of South America, through the equally naked-tailed Couscous, Ba- 

 lantia, of the Indian Isles, to the true Phalangers ; and from these 

 to the Petmirists directly on the one hand, and by means of the 

 Pseudocheirs to the Koalas on the other. 



On the prehensile power of the tail Mr. Ogilby particularly in- 

 sists, as on a faculty possessed by the greater number of the Pedi- 

 mana, and as one which is, in truth, almost confined to them : only 

 three known genera belonging to other groups, Synetherus, Myrme- 

 cophaga, and Cercolepies, being endowed with it. He remarks on 

 this faculty as on one of considerable importance, affording as it 

 does, in some degree, a compensation for the absence of opposable 

 thumbs on the anterior limbs. Combined with the prehensile tail, 

 in every known instance, wiiether among the PerUmana or in other 

 groups, is a slowness and apparent cautiousness of motion, not ob- 

 servable in any of the Quadrumana except in the Nycticebi. In none 

 of the true Quadrumana is the tail prehensile. 



Another evidence of the distinctness, as two groups, of the Qua- 

 drumana and the Pedimana, is furnished by their geographical distri- 

 bution. Tlie Quadrumana are strictly confined to the limits of the 

 Old World : the Pedimana, almost as exclusively to the New World; 

 for Mr. Ogilby considers the continent of Australia to belong more 

 properly to America than to Asia. The very few: apparent excep- 

 tions that occur to this latter position are in the presence of some 

 species of Phalangers in the long chain of islands that connect the 

 south-eastern shores of Asia with the north-eastern coast of Aus- 

 tralia ; islands which may, in truth, be fairly regarded as belonging 

 partly to the one and partly to the other, and the productions of 

 which might consequently be expected to partake of the character 

 of both. 



Mr. Ogilby subsequently adverts to another Pedimanous animal, 

 the Aye-Aye of Madagascar, constituting the genus Cheiromys ; re- 

 specting the affinities of which he speaks with hesitation, because, 

 having never had an opportunity of examining the animal itself, he 

 is acquainted with its characters only at second-hand. He is, how- 

 ever, disposed to regard it as representing a third group among the 

 Pedimana, to be placed in a station intermediate between the Mon- 

 keys of the New World and the Didelphidee. With the latter he 

 would, in fact, be disposed to associate it, were it not destitute of 

 the marsupial character which belongs to all the other animals com- 

 prised in that group. In some of the Didelphidee, the Phalangers 

 and Petaurists especially, there is a marked approximation to that 

 rodent form of incisor teeth which obtains in Cheiromys, and which 

 has hitherto been regarded as especially attaching to it an abnormal 

 character. 



Man is the only other animal furnished with hands ; and how- 

 ever distinct he may be as regards his moral and intellectual powers, 

 lie must, zoologically, be considered on physical grounds. By his 

 structural characters he becomes associated with all those of which 

 mention has previously been made in Mr. Ogilby 's communication ; 



Third Series. Vol. 9, No. 54. Oct. 18.S6. 2 N 



