G82 DR. D. .1. CUNNINGHAM ON [Jlllie 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 an- 

 terior 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 

 convexitv which extended to the root. 



Vertebral column. — The vertebrae were 90 in number — 7 cervical, 

 1 5 dorsal, and 6*8 lumbo-caudal. The atlas and axis were fused to- 

 gether, 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 laminee, 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 Ur. 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 BrightwelFs 

 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 tins and tail were of the same colour as the back." 

 Gray*, Lilljeborgf, and Belli, 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 ot 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 Whales & Dolphins in 

 Brit. Mas 1868. 



t Lilljeborg, Mem. on Cetacea, Ray Soc. 1866. 

 | Bell, British Quadrupeds (2nd edition), 1^74. 



