This animal has the harsh fur without any under-fur of Phocarctos Hookeri; but it entirely differs from that animal in the colour of the fur. This cannot arise from the greater age of the animal, as it is not nearly so large as the half-grown P. Hookeri in the British Museum.
In the dark blackish-brown colour of the fur and the pale-brown colour of the nape, and in the absence of the under-fur, this Seal resembles the adult Neophoca lobata from Australia; but in that species the pale colour extends all over the crown, while in the young male Otaria jubata there are only a few paler scattered hairs on the middle of the crown and nose.
Dr. Murie represents the skull of a nearly full-grown male and of a female nearly of the same age (P. Z. S. 1869, p. 103. f. 1, 2). They greatly differ, the nose and the palate being much wider in the male than in the female, and the teeth in the male (but this may be only an individual peculiarity) were much worn down.
He observes, “the whole of the palate is much narrower than in the male of the same size, especially in the maxillary region, and the teeth are much weaker and more sharply pointed.”
He observes, “The young of both sexes are alike of a dark brown or very deep chocolate colour. The males about a year old retain somewhat of the chocolate tint of their youth, which, however, is paler, and subsequently changes annually as the coat is shed. The females of equal age assume a dark grey hue dorsally, while the abdominal parts are light yellowish. As they grow older they alter little.
“Males a couple of years old or more become of a rich brown shade on the back and sides, and lighter or yellowish beneath. Old males alone are maned.
“There is a sparse underwool on the young, which sensibly diminishes with age.
“The skulls of the adult male and female differ considerably, the latter being comparatively the narrower of the two—the former possessing a somewhat different form of teeth, besides proportionally immense canines.
“The teeth of Otaria jubata are subject occasionally to a peculiar wearing, of a median constricted character.