GENERAL OBSERVATIONS. 7 



" Considering the very different attitudes assumed by the Tri- 

 checliidce and Otariidce as compared with the Pliocidcef he further 

 adds, " it is remarkable how very little deviation follows in the 

 muscular development. The two former, as might be antici- 

 pated, present a general agreement, especially in the mode of 

 implantation of the muscles of the hind leg, and in this respect 

 recede from the Seal, yet but slightly." * 



In respect to the position and character of the viscera, a gen- 

 eral agreement has beeen noted with those of the other Pinni- 

 peds, and they present nothing that calls for special notice in 

 the present connection. As Dr. Murie has stated, there is little 

 appreciable difference exhibited throughout the Pinnipeds in 

 the construction of the alimentary canal. " It is simply that of 

 a Carnivore, with, however, a moderate-sized caecum. The great 

 glandular superficies and correlated large lymphatics point to 

 means of speedy and frequent digestion 5 and in the Walrus 

 these apparatus are extraordinarily developed."! 



In accordance with the characters already given (p. 3), if any 

 subdivision of the Pinnipeds into groups of higher rank than 

 families is to be made, it seems evident that the Odobcenidw 

 and Otariidce are to be collectively contrasted with the Phocidw; 

 in other words, that to unite the Otariidce and Photidce as a 

 group of co-ordinate rank with the Odobcenidce is to lose sight 

 of the wide differences that separate the two first-named fami- 

 lies, as well as of the many important features shared in com- 

 mon by the Odobcenidce and Otariidce, by which both are trench- 

 antly separated from the PJiocidce. 



Although the Walruses are now very generally recognized as 

 constituting a natural family of the Pinnipeds, ranking co-ordi- 

 nately with the Eared Seals on the one hand and with the Earless 

 Seals on the other, the affinities of few groups have been more 

 diversely interpreted. As early as the thirteenth century, the 

 author of the " Speculum Kegale", one of the earliest works re- 

 lating to natural history, in which the Walrus is mentioned, 

 stated distinctly that the Walrus was an animal closely related 

 to the Seals ; and we find that nearly all natural-history writers 

 prior to the middle of the eighteenth century who referred to the 

 Walruses, gave them the same association. It was the technical 

 systematists of the last half of the eighteenth century who 

 broke up this natural juxtaposition, and variously grouped 



* Trans. Zool. Soc. Lond., vol. vii, 1872, p. 459. 

 t Trans. Zool. Soc. Lond., vol. vii, 1872, p. 461. 



