Art. XI.—–On some Points in the Anatomy of a Species of Sea-bear caught off Sumner, Canterbury, New Zealand; with Notes on the New Zealand Eared Seals. (Abstract.)
Communicated by J. T. Meeson, B.A.
[Read before the Philosophical Institute of Canterbury, 1st October, 1891.]
In this paper (which will be published in extenso in a future volume, when the necessary drawing—which, for want of a
competent artist, are not yet completed—are prepared) the author gives an account of his dissection of a specimen of Arctocephalus forsteri, presented to the Museum by the proprietor of the Heathcote Hotel. It had been caught in 1890 off Sumner, and since then, till its death in July, it had lived in captivity. The anatomy of so few species of the eared seals is known that every addition to our knowledge cannot but assist in reducing to something like fixity the extraordinary diversity of opinion and of classification that exists at present with regard to the Australasian Otaries. The present communication deals chiefly with the anatomy of the viscera and brain. The preparation of a catalogue of the New Zealand collections in the Museum, and the determination of the subject of these notes, has necessitated an examination and comparison of the specimens in the collection there Here the greatest confusion in the species was found, unmistakable hair-seals being identified as fur-seals. The author is inclined to agree with the classification of the seals by Sir W. Turner, in his monograph in vol. xxvi. of “The Scientific Results of the Voyage of H.M.S. ‘C hallenger,’” in preference to that advocated by Mr. Beddard, the present prosector of the Zoological Society of London. This anatomist, in his valuable paper in the Transactions of the Zoological Society, vol. xii., p. 379, suggests the inclusion of all the eared seals in two genera only—Otaria and Arctocephalus—including in Otaria only the single species Otaria jubata, a hair-seal, while all the remaining species would fall under the genus Arctocephalus. This arrangement would group together both hair-seals or sea-lions, and fur-seals or sea-bears. The different species of eared seals, with the exception of Otaria jubata, seem to agree so closely in their anatomical details that it is very difficult to state any differentiating characters. The character of their fur, however, appears to the author a mark so distinctive and discriminating that he prefers to follow the proposal of Sir W. Turner in dividing the remaining seals, after the separation of Otaria jubata, into sea-lions and sea-bears, assigning to the former the name of Eumetopias, and retaining for the latter the designation of Arctocephalus. Of the New Zealand seals the Auckland Island hair-seal would fall into the first, as Eumetopias hookeri (the males of which are at present incorrectly labelled in the Museum as Otaria forsteri), and the specimen common to our coasts as Arctocephalus forsteri; the species denominated under the name cinereus, or grey seal, being the female of Arctocephalus forsteri. Sir William Turner, in the monograph just referred to, includes under Eumetopias the species cinerea, of Peron, the grey sea-lion of New Zealand and Australia. “This hair-seal,” he says, “was first noticed by Peron.… In a
recent memoir, however, Mr. J. W. Clark (Proc. Z.S. Lond., 1884, p. 188) gives a careful description of the skins and more salient features of the skull of several specimens of the grey sea-lion from the Seal Rocks, near Port Stephens, New South Wales, which animal he identifies with the Otaria cinerea of Peron.” On consulting Mr. Clark's paper, one is surprised to discover that he is dealing with four stuffed specimens, all with underfur (Peron's seal being undoubtedly a hair-seal), with a not quite full-grown skeleton, and a skin and a skull of an animal of about the same age which had been taken at the same time and place as those of the four stuffed specimens. From the descriptions given by Mr. Clark, the author of the present paper is convinced that they all belong to the same species as the New Zealand fur-seal (Arctocephalus forsteri, Lesson), for they cannot be Peron's cinerea, inasmuch as it was a hair-seal. There is at present no evidence that there is a grey hair-seal of New Zealand; and the author agrees with Mr. Allen, in his “History of the North American Pinnipeds,” that it would be well, on account of the uncertainty of identifying the species Peron meant to apply that name to, to discard it altogether. The author is personally inclined to believe that Peron applied the term to a female of Eumetopias hookeri, which is grey or almost white in colour. In the New Zealand region, therefore, there are only two eared seals—one of them a hair-seal (Eumetopias hookeri), inhabiting the Auckland Islands, and, so far as the author can discover, never yet taken in New Zealand; and a fur-seal (Arcto-cephalus forsteri), which is common on both coasts of the South Island, frequents the Chatham Islands, and inhabits also the Seal Rocks, near Port Stephens, New South Wales, but unrecorded (so far as the author knows) from the Auckland Islands with any certainty. The great confusion among the species has arisen from the marked difference existing between the young at different ages and different seasons, and between the sexes, in their external appearance, and the great changes that take place in their bony framework from youth to adult life and in old age. The same species has been described by a different name under each of these conditions, and it is matter for little surprise that the synonymy of the various species is as confused as it well can be, and is a study in itself to unravel.
The sea-leopard (Ogmarinus leptonyx), so common on our shores, is not an eared seal—that is, it has no external ears—and is placed in a distinct family—the Phocidæ—of the fin-footed carnivorous animals, and is the third and remaining species of seal belonging to the New Zealand fauna.