90 Mr. Ball on the Species of Seals inhabiting the Irish Seas. 



being simple, approaching closely in form to those of some of the genus Del- 

 phinus, while in Phoca they have always more than one root. From conversation 

 with Professor Nilsson, I learned that the Halichcerus of the Baltic is of solitary 

 habits ; in this it diflPers from ours, which is often seen in small herds. He 

 attached great importance to colour as a character, so much that I am inclined to 

 think it probable the species will ultimately be proved to be distinct, for the 

 changes of colour from age, season, sex, &c. of our Halichoerus seem so various as 

 to offer no guide to a determination of species. In the many specimens I have 

 seen, I do not recollect that any two were precisely similar. The very young 

 females are generally of a dull yellowish white, with rather long hair, which falls 

 ofiF in about six weeks after birth, and gives place to a shorter and more shining 

 coat of a warm, dingy yellow, variously blotched with blackish gray ; the whole 

 gradually growing more dull, the blotching more indistinct, and a general dark 

 shade spreading on the back as the animals advance in age. A young male in my 

 possession has long yellowish hair slightly tinged with brownish black on the back ; 

 is black on the nose, chin, and cheeks, and on the palms of the fore-feet. The 

 hair of the adult female Halichcerus, when dry, is considerably recurved, and is 

 flattened on its upper surface, as if scraped with a knife. The optical effect of 

 this structure is curious, for when the animal is turned with its head towards the 

 spectator, it appears of a uniform silvery grey, and, when turned the other way, it 

 seems of a sooty brown colour, while the spots or blotches are only distinctly 

 visible from a side view. The hairs of the whiskers of all seals are remarkable 

 in form ; those of the Halichoerus are flattened in one direction, and contracted at 

 regular intervals in the other, so that being viewed in front they appear linear, 

 while, seen from the side they seem moniliform : they vary in colour in different 

 individuals. The Halichoerus is easily distinguished from other seals by its 

 straight profile, fierce aspect, and more lengthened proportions. The develop- 

 ment of its skull is very much smaller than in the genus Phoca, the brain of one 

 of the latter being as large as that of a Halichoerus of twice its length, and the 

 intellectual powers seem to hold the same ratio. I recognized on sight, in the 

 remains of Donovan's Phoca Barbata now in the British Museum, the skin of a 

 Halichcerus much deformed by the mounter, and I find my observation has since 

 been confirmed by Professor Nilsson. This seems to be the individual described 

 by Parsons as the long-bodied seal, and it appears to have been on the authority 



