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Show 1883.] PROF. FLOWER ON THE DELPHINID/E. 481 description enables us to judge, there is absolutely nothing to distinguish it, either in the external proportions, the distribution of the colours, or the osteological characters, from tbe common T. tursio of the European seas. It is true that in the only skeleton described it is stated that but 12 pairs of ribs are present; but as the last pair is so often wanting or lost in preparation, this is of little consequence, especially as the total number of vertebrae is given as 64. An animal of this genus is also found in the North Pacific off the Californian coast, the "Cow-fish" ofScammon, Tursiogillii of Dall1; but there is nothing in the description of the external characters, *' based upon two momentary observations," the habits, or the one portion of the animal actually obtained, to distinguish it from T. tursio of the European seas. Perhaps the skull in the Paris Museum, sent from Monterey, California, in 1879, belongs to this form if distinct. It is 610 m m . in length, and with comparatively few and large teeth, -Qin number, and 7 m m . in antero-posterior diameter at the base. It is very like the skull of Gray's T. metis, figured in tbe ' Zoology of the Erebus and Terror.' In the International Fisheries Exhibition of the present year, among the beautiful and instructive models of Cetaceans and other aquatic animals shown by the United States Commissioners, are coloured casts in papier mache of an animal of this group, and of the heads of two individuals marked male and female, the former being apparently the same individual as the entire animal. These are labelled Tursio subridens, True. M S . On comparing them with the figure of D. tursio in the Trans. Zool. Soc. vol. xi. pl. 1, from the coast of Wales, the only noticeable difference is in the colour of the lower jaw and chin. In the figure this part is entirely white. In the male American specimen it is black, this colour extending farther back in the middle line below, than on the sides of the jaw, and terminating in a point at about the level of the eye. This might have been thought to constitute a specific difference; but in the cast said to be that of a female of the same species there is only a dark gray patch confined to the anterior part of the under surface of the chin ; so that with the totally white-throated English specimen, we have three different and quite distinct conditions of the coloration of this region-one, that of the American female, being exactly intermediate between the other two. Until a larger series of specimens are examined, it would not be safe to establish specific distinctions on such characters, especially when we bear in mind the different descriptions of the colours of animals attributed to this species given by Fischer. A skull attributed to this form, presumably of one of the same individuals, is in the collection : it is that of a not fullv adult animal; and on comparing it with a specimen in the same state of development taken off the coast of Kent, near Margate, 1 Scammon, 'Marine Mammals of the North-western Coast of North America,' pp. 101 and 288 (1874). |