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Show 682 DR. D. J. CUNNINGHAM ON [Julie 20, very probable by the fact that in structure it is exactly similar to the dorsal fin. It is composed of the same dense, almost glistening fibrous tissue, in the meshes of which is very little oil. The dorsal fin had a falciform posterior border; and its base was prolonged for a short distance towards the tail by a well-marked ridge. The flipper had a very characteristic appearance. The anterior and longest margin presented a uniform convex curve from the root to the tip. The posterior border was slightly concave from the tip to about the middle ; here it suddenly bulged out into a convexity which extended to the root. Vertebral column.-The vertebrae were 90 in number-7 cervical, 15 dorsal, and 68 1 urn bo-caudal. The atlas and axis were fused together, so as to constitute one bone, the double nature of which, however, was indicated behind by two fissures, one on each side, which partially separated the laminae, and in front by a partial plate of cartilage intervening between the bodies. The other five cervical vertebrae were free. The transverse processes were flat, directed somewhat forwards and imbricated. Such being the distinctive characters of this Dolphin, we must now proceed to determine the species to which it belongs. It presents points of similarity both to D. albirostris and to D. acutus or leucopleurus. D. albirostris was first figured and described by Brightwell in 1846, under the name of D. tursio (Fabr.), in the 'Annals and Magazine of Natural History' (vol. xvii.) ; but Dr. J. E. Gray, recognizing this error of nomenclature, pointed out that it was a new species, and gave it the specific name of albirostris. The specimen described by Brightwell was a female caught off Yarmouth, and it measured 8 feet 2 inches in length. The following is Brightwell's description:-"The colour of the upper part and sides a very rich deep purple-black. The external cuticle was of a soft and silky texture, and so thin and delicate that it was easily rubbed off. The nose and a well-defined line along the upper jaw, and the whole of the lower jaw and belly, were of a cream-colour, varied in some parts by a chalky-coloured white, contrasting beautifully with the rich black of the body. The fins and tail were of the same colour as the back." Gray*, Lilljeborgt, and Bell J, all follow this description; and it may therefore be considered the source from which they have drawn their information ; moreover Gray and Bell have reproduced the figure, the former on a larger and the latter on a smaller scale. The drawing represents an animal of an entirely different mould from the Dolphin I have described. The head has not the same massive appearance, but is characterized by the great prolongation forwards of the jaws ; whilst, behind the dorsal fin, the body tapers sharply and uniformly towards the caudal expansion, showing nothing of the hump or rudimentary dorsal fin which constituted * Gray, Cat. of Seals & Whales, 1866; Synopsis of Wbales & Dolphins in Brit. Mus 1868. t Lilljeborg, Mem, on Cetacea, Ray Soc. 1866. | Bell, British Quadrupeds (2nd edition), 1874. |