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Show 562 DR. J. E. GRAY ON THE BOTTLENOSED WHALES. [Nov. 12, specimens, all obtained at the same time from the same school of these Dolphins from the Firth of Forth. In the skull of the old male the sheath of the opening is nearly flat below and on the sides, the lateral ridges being almost on the edge. In the skull of the full-grown female the sheath of the hinder nasal opening is nearly similar to that of the male, but the sides are more convex and swollen. The third skull of a full-grown animal, the sex of which was not marked, is very like the skull in the British Museum that Colonel Montagu described as Delphinus truncatus, and it has, like the latter, all the teeth much worn down and truncated. They both differ from the skull of the adult male and of the full-grown female in the sheath of the hinder nasal aperture being rather narrower, more deeply impressed in the centre, and in the lateral keel being more within the margin, making the side of the sheath more convex and rounded. Being very desirous of obtaining information bearing on the geographical distribution of Cetacea, and hearing that Mr. Moore, of the Liverpool Museum, had recently obtained the skull of a Bottlenosed Whale (Tursio) from the west coast of Africa, I requested him to send it to the British Museum for examination and comparison. It is intermediate, in some respects, between the skulls of the Tursio truncatus, of the English coast, and T. metis, the locality of which is unknown. It has the large teeth and long teeth-line of the T. truncatus; indeed the teeth-line is above half an inch longer than in that species ; but the beak of the skull is rather slender: in this latter character it is more like T. metis; but that species has a rather shorter teeth-line even than T. truncatus. If it were not that I have lately observed that Dolphins that differ very little from each other in the form and proportion of their skulls have very different external characters, I should be inclined to think that T. truncatus, T. metis, and the specimen from West Africa were all of one species, varying a little in the form of the skull; but we must leave this question for further examination, more especially as different authors have described the living Tursio that came under their examination as being very differently coloured externally, and only record that a species of Tursio is found on the west coast of Africa, as well as in the North Sea, the Bay of Biscay, the Mediterranean, and the Red Sea. The following are the measurements of the West-African skull:- inches. Length entire 22| of beak 13 of teeth-line 11 Width of brain-case 1()| of beak at notch 5-J_ of beak between tenth and eleventh tooth .. 3T-W 1 - The skull was presented to the Liverpool Museum by Mr. J. Lewis Ingram, of the Temple, who obtained it at the Gambia. |
