If I am not deceived by the prepared skins, the flap appears to be longer in the adult than in the young specimens; and judging from the specimens in the Museum, it is longest in _Callorhinus ursinus_, and it gradually becomes shorter in _Arctocephalus antarcticus_, _A. falklandicus_, _Phocarctos Hookeri_, _A. cinereus_, _Otaria jubata_, and _A. nigrescens_. It is very short in _Neophoca lobata_ and _Eumetopias Stelleri_. The “Prodrome of a Monograph of the Pinnipedes,” by Mr. Theodore Gill, wherein he named several genera of this group, and a paper by Dr. Peters on the _Otariæ_ of the Berlin Museum, in the ‘Monatsbericht’ for May 1866, have induced me to reexamine the skulls and skeletons in the British Museum. I may observe that Dr. Peters considers all the Eared Seals one genus, but has divided them into seven subgenera, to each of which he gives a distinctive name. Dr. Peters’s paper is interesting as determining the specimens described by Pander and D’Alton, Johann Müller, and other German naturalists, as well as describing the more recently received specimens in the Berlin Museum, which certainly is one of the most important on the Continent. Captain Thomas Musgrave, in a work entitled ‘Cast away on the Aucklands,’ 12mo, 1866, pp. 141 and following, gives a very interesting account of the habits and manners of the Lion-seal, showing how unlike they are in their habits to the Seals without ears (Phocidæ). The female brings forth her young far inland, and has to teach them to take to the water which is to be their future home. Captain Weddell gives nearly the same account of the habits of the Fur-Seal, as does also Mr. Hamilton (in Ann. & Mag. Nat. Hist. 1839, p. 87). Mr. J. A. Allen, in the ‘Bulletin of the Museum of Comparative Zoology’ at Harvard College, Cambridge, Mass., has published (1870) an essay on the Eared Seals (Otariadæ), with detailed descriptions of the North-Pacific species. He divides the family into subfamilies:— Subfam. 1. _Trichophocinæ_, without under-fur, and containing the genera OTARIA, EUMETOPIAS, ZALOPHUS. Subfam. 2. _Eulophocinæ_, with thick under-fur, containing CALLORHINUS and ARCTOCEPHALUS. He gives figures of the skulls of different ages of the North-Pacific species.