Supplement to the catalogue of seals and whales in the British Museum

by John Edward Gray

The length, abundance, and, indeed, the presence or absence of the under-fur greatly depend on the season at which the specimen is obtained or observed. It is true that the sealers call some seals hair- and others fur-seals; but that is only because what they call hair-seals never had more than a very small quantity of under-fur in the fur-season; but, on the other hand, many fur-seals at some seasons have only a small quantity of the under-fur which is so long and abundant at other periods.

Difficult as it is for the zoologist to distinguish the species by their external appearance, the skins of the different species of Fur-Seals are easily distinguished by the dealers, even when they are wet, showing that the practical fellmonger is in advance of the scientific man in such particulars, as the dealers in whalebone were in regard to the distinction of the species of the Whale by their baleen (see Zool. Erebus & Terror).

The longer hairs of the Fur-Seals are very slender and pale-coloured at the basal half of their length, and thicker and darker at the upper half, and often have a white tip. The basal half is subcylindrical, the upper half is flat, tapering at each end. The absolute length of the under-fur differs in the various species. Judging from the old and young specimens of A. nigrescens, the hairs seem to be longer, both absolutely and relatively to the under-fur, in the young than in the adult animals. The hairs of the Hair-Seals are shorter, flat, channelled above, and gradually tapering from the base to the tip, merely contracted at the insertion into the skin. The breadth of the hairs seems to vary in the different species; and in the younger specimens there are to be observed some soft hairs like the under-fur of the Fur-Seals.

The Fur-Seals are Callorhinus ursinus, Arctocephalus antarcticus, A. nigrescens, A. cinereus, A. Forsteri, A. falklandicus, Eumetopias Stelleri, Arctophoca Philippii.

The Hair-Seals are Otaria jubata, Phocarctos Hookeri, Arctocephalus nivosus, Zalophus Gilliespii, Neophoca lobatus.

Dr. Peters, in his two papers on the Eared Seals (Otaria) uses the length of the ears and the existence or non-existence of the under-fur, as well as the characters used by Mr. Gill and myself, to separate the species of these animals into subgenera.

The length of the ears may probably afford good characters for the separation of the species and groups, if they can be observed in the living animals. As yet, only one species of these animals, the Sea-lion or Sea-bear (Otaria leonina), has been observed alive in Europe; so that Dr. Peters’s notes could only be derived from the examination of more or less carefully preserved skins; and, I fear, little dependence can be placed on them.

The form of the hinder opening of the nostrils and the form of its front edge, when only one or two skulls of a species were examined, have been regarded as constituting a good character; but when an extensive series of the skulls of a single species, or of several species, have been examined, that part is found to vary considerably as to the width of its different parts, and especially in the form of its front edge. As far as my observations have extended, the hinder opening of the nostrils appears to become narrower, and especially its front edge, as the animal becomes adult or aged; and in the skulls of the younger specimens it is broader, shorter, and the front edge is broader and more truncated or straight, with only a slight rounding at the sides.

The position of the grinders as regards the front part of the zygomatic arch is a good character for the distinction of the species, especially if a series of skulls from animals of different ages, and from the same locality, of each species are compared together; and it is the same with the rooting of the grinders themselves. But when adult skulls of different species are compared together, the forms of the skulls are so altered, the grinders generally so worn and altered by age, and their position in different species so similar, that the distinction of the species then becomes more difficult.

The flap of thick bald skin produced beyond the hinder toes varies in length as compared with the toes, in the length of it before it divides into lobes, and the length of the lobes themselves in different species, and thus affords characters for their separation; but it is difficult to determine the proper length of it and its parts from a preserved specimen in the Museum. It is apt to be unnaturally stretched in length and width by the preparer, and it shrinks as it dries long after it is placed in the Museum.