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Show 756 MR. J. W. CLARK ON THE EARED [Nov. 18, plication from Captain Musgrave's account; for he nowhere mentions using seal-skins for warm clothing, though he suffered much from cold ; but he does speak of the excellent leather he thinks might be made out of the skin of the Sea-lion (p. 81). Turning now to the skulls, I find that the two smaller ones correspond exactly with those named Arctocephalus hookeri by Dr. Gray in the Zoology of the voyage of the 'Erebus' and ' Terror'* . I have compared them with the type specimen, and with the others preserved in the British Museum, all of which were, I understand, brought home by Sir J. C. Ross's Antarctic Expedition. The correspondence is more complete than would be imagined from a mere inspection of the plate; for a line drawn across the hinder edge of the zygomatic process of the maxilla ought to pass through the centre of the penultimate molar, whereas in the plate such a line would pass between that tooth and the last of the series. Before considering these skulls more minutely, let us pass to the large skull labelled "male adulte," and I think we shall find that they all have certain very marked characteristics in common. No one who looks at this skull (see figures pp. 754 and 755) can fail, I think, to be at once struck by two points in its conformation:-its great length in proportion to its width, so that it closely resembles the skull of a Polar Bear; and the length, the massiveness, and the uniform vertical height of the lower jaw. It measures 13" in length, by 7|" in width (the latter measurement being taken across the zygomatic process of the squamosal); that is to say, the length : width : : 2 : 1 nearly, while in a series of skulls of Otaria jubata the length : width : :*3 : 2. The lower jaw is 9|" long, 2£" in height immediately behind the canine, and 2£" behind the last molar. The same characters, relatively, are to be found in the smaller skulls : they exhibit similar relations of length to width, and the lower jaws are equally long and of equally uniform height. On reversing the male skull the palate is seen to be deeply hollowed out in front, and to narrow gradually behind the zygoma, becoming at the same time nearly flat. The palatine bones are, in consequence of the great length of the skull, much elongated, and remarkably curved, thickened, and bent outwards at their posterior extremity. The pterygoid plate of the alisphenoid is, for the same reasons, a very long and stout pillar of bone, pierced by a wide alisphenoid canal. The pterygoids themselves are small; but in this specimen they are so broken that their precise form is difficult to distinguish. The palatine opening is long and narrow. The mastoid portion of the periotic is produced into a long peg-like process; and there is no union between the periotic and the basioccipital. The foramen lacerum posterius is confluent with the foramen lacerum medium. If we now look at the two smaller skulls we shall see that the palates are equally concave, that they narrow and become flat at the 6ame point, that the palatines and pterygoids are similarly elongated and are of like shape. The palatine opening is proportionally * Page 4, Beasts, plate xv. (skull). |