Above black-grey, more greyish yellow on the head and neck, brownish black _beneath_; the base of the limbs of a rusty brown, shining; lips and lower jaw principally rusty brown; hair of beard in six rows, partly black, partly quite white, partly black with white base. The outbristling (prominent bristly) pointed hairs are rusty brown at the base, black at the end, on the back mostly with very short rusty-yellowish points, and on the head and neck with somewhat longer ones. On the sides of the belly the ends of the coarser pointed hairs are either uniformly brownish black, or are very short rusty-red ones. The thick under-hair is rusty red. The hairs on the upper surface of the neck are 22 millims. long; those on the middle of the back 18, and those on the middle of the belly 11 to 12. The dense short hair on the back of the hand extends only to the _middle_ of the same, not extending to the ends of the fingers, the ends of which are furnished with very small nails. In like manner, the very similar hair on the back of the foot does not extend to the last “Phalangen?” of the middle toe. The nail of the large outer toe is small, flat, and cut off short outside; that of the fifth inner toe is a little larger and cut off abruptly on the inner side. The very developed long nails of the three centre toes are of the form of keeled tegulæ, and remote along their whole length by the emarginations of the skin of the foot. The skin-flaps of the foot are equally long; and usually those of the centre toes are much smaller than the side ones, of which the outside one (the great toe) is the broadest. The scrotum, under the anus, is bare.—_Peters_, _l. c._ p. 277. I have not seen this skull; but I believe the alteration Dr. Peters made in his second paper is a mistake. The figure of the skull of his _Otaria Philippii_ has no resemblance to the skull of my _O. nigrescens_. It is more nearly allied to the skull of _O. Stelleri_ from California, agreeing with it in having a vacant space with a pit in the bone between the fourth and fifth upper grinders on each side, looking as if a grinder had fallen out and the cavity had been filled up. The subgenus _Arctophoca_ of Dr. Peters’s first essay, not as modified in his second one to contain _O. falklandica_ (_nigrescens_), chiefly differs from Gill’s genus _Eumetopias_ (which was formed on my description and figure of the skull of _O. Stelleri_ or _californiana_) in the fifth upper grinder not being so far back, but in a line with the back edge of the orbital process of the zygomatic arch instead of far behind it, as it is in _Eumetopias_. Dr. Murie, most curiously, considers the skull described by Dr. Peters to be the same as I have described as _O. Hookeri_ (P. Z. S. 1869, p. 108).