Royal Physical Society. 423 



This statement receives considerable support from the manner 

 in which the order Canivora itself has been divided by differ- 

 ent authorities, as well as by the various positions assigned to 

 the different genera comprising the order. The external cha- 

 racters of the different members composing the Carnivora are 

 sufficiently distinct, and might be supposed to present little 

 difficulty in determining the lesser sub-divisions. This, how- 

 ever, is far from being the case, as the different classifications 

 of authors abundantly testify. It is only of late years that 

 the importance between Morphological, or essential, characters, 

 and those termed Teleological, or adaptive, have been fully re- 

 cognised as forming a true basis for a scientific classification. 

 Morphological relationship throughout the series of the animal 

 kingdom can only be ascertained by the aid of embryological 

 investigation and comparative anatomy. In any large assem- 

 blage of animals, where a general similarity of structure extends 

 throughout the different modifications of form, the difficulty 

 of finding essential characters for the minor sub-divisions will 

 doubtless become much greater and less certain. Conceiving, 

 however, that the natural affinities of the animal kingdom can 

 only be scientifically based on characters truly essential, and 

 independent of adaptive differences, it appears from investi- 

 gation that the base of the skull is especially furnished with 

 these characters. And in the subsequent remarks on the Am- 

 phibious Carnivora, and on the skull belonging to the eared 

 section of the order, this portion of the vertebrate skeleton 

 will be chiefly considered. Without entering into details, it 

 will be sufficient at present to state, that Mr Turner has di- 

 vided the order Carnivora into four families, — Ursidce, Fe- 

 lidm, Canidw, and Phocidw, — founded upon essential charac- 

 ters, principally derived from the base of the skull. These 

 characters mainly depend upon the structure and formation of 

 the pterygoid bones and processes, the form of the mastoid 

 and paroccipital processes and tympanic bulla, and on certain 

 foramina for the transmission of nerves and blood-vessels. In 

 applying these characters to the amphibious family of the 

 Carnivora, it will be at once apparent, from an examination of 

 two crania, representing the inauriculate and auriculate sec- 

 tion of the seals, that they are very distinctly separable. 

 vol. i. 2 Q 



