90 MAMMALIA. 



"VVTiale, Mr. Brown states that " the whiskers consist of nine or 

 ten short rows of bristles, the longest bristles anteriorly. There 

 are also a few bristles on the apices of both jaws, and a few hairs 

 stretching all along the side of the head for a few feet backwards. 

 On the tip of the nose are two or three rows of very short white 

 hairs, with fewer hairs in the anterior rows, more in the posterior. 

 I have reason to believe that some of these hairs are deciduous, as 

 they are often wanting in old individuals." Notwithstanding 

 their abnormability of external form, and of their mode of life, 

 as compared with the generality of the class Mammalia, it is thus 

 seen that even the great toothless "Wliales tend to exhibit one of 

 the usual characteristics of the class to which they appertain, 

 which is to be clad with hair or fur ; and it is highly probable 

 that it has been overlooked in sundry species of them. 



Of the three subfamilies of Bakenopteridce, the ■ Mer/apteriiue 

 comprise three genera — Megapfera, Poescopia, and EscltricJitius; 

 the Plit/salime comprise Bencdeiiia, Phi/salus, Citcierhis, and Sib- 

 hahllus ; and the Balwnopterince consist of one genus only — - 

 Bahenopterus. 



Many naturalists are of opinion that Dr. Graj^ carries the dis- 

 crimination of these genera to excess ; but, after briefly assigning 

 certain distinctions, it is remarked by him that " the student 

 miist not run away with the idea that because the characters of 

 the genera here given are taken from a few parts of the skeleton, 

 they are the only differences that exist between the skeletons of 

 the different genera and species. The form of the head, and the 

 peculiarities of the cervical vertebraj, of the ribs and of the blade- 

 bone, have been selected, after a long and careful comparison 

 of the skeletons, as the parts which afford the most striking- 

 characters that can be the most easily conveyed to the mind of 

 the student in a few words, and therefore best adapted for the dis- 

 tinction of the genera and species." It is at least tolerably certain 

 now that the species of these huge marine creatures are sur- 

 prisingly numerous, instead of their being comparatively very few, 

 as was supposed formerly ; and several of them have only recently 

 become adequately recognised, whilst by far the greater number 

 are still insufficiently Icnown to be regarded as definitely estab- 

 lished. Here we can do little more than briefly indicate the 

 principal forms. 



