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Show 1883.] MR. BOULENGER ON A NEW SPECIES OF BUFO. 139 epithalami, just as in the Ganoids. Thus, in cerebral structure, as in other respects, the Ganoids and the Teleosteans are as closely related to one another as they are different from the Selachians. With respect to the chiasma of the optic nerves, the exact nature of that structure has not yet been properly elucidated either in the Selachians or in the Ganoids. But, whatever m a y come of such an investigation, the establishment of the existence of a true chiasma in the Ganoids, and of its absence in Teleosteans, can have but little bearing on the question of their affinities, since Wiedersheim has shown that a simple decussation of the fibres of the optic nerves, as in ordinary Teleosteans, takes place in many Lizards. I a m no great believer in the permanent value of sharply drawn distinctions of any kind in zoology; but, assuredly, if there is any such distinction to be drawn on the basis of our present knowledge among the higher fishes, it is between the Ganoids and the Plagio-stomes, and not between the Ganoids and the Teleosteans. At page 373 of Dr. Giinther's work 'On the Study of Fishes,' published in 1880, he affirms broadly and without the least qualification that, though " we find not a few analogous forms in both series " [namely the Ganoidei and the Teleostei], yet " there is no direct genetic relation between those fishes, as some naturalists were inclined to believe." I imagine that I a m included among the naturalists thus summarily disposed of, since, in 1876, I expressed the opinion that " in Amia there is an even closer approximation between the Ganoids and the Teleosteans than can at present be shown to exist between any Ganoids and the Dipnoi; while the differences between the Dipnoi and the Chimseroidei and between the Chimseroidei and the Plagiostomi respectively are not less than those between the Ganoids and the Dipnoi" *; and I objected on these grounds to the adoption of the group of " Palseichthyes " proposed by Dr. Giinther. W h e n objections are ignored without being refuted, or even discussed, I suppose that the best way is to emphasize them afresh; and I do this, on the present occasion, by expressing m y conviction, first, that there are no two large groups of animals for which the evidence of a " direct genetic connexion " is better than in the case of the Ganoids and the Teleosteans; and, secondly, that the proposal to separate the Elasmobranchii, Ganoidei, and Dipnoi of Miiller into a group apart from, and equivalent to, the Teleostei appears to m e to be inconsistent with the plainest anatomical relations of these fishes. 2. Description of a new Species of Bufo from Japan. By G. A. BOULENGER, F.Z.S. [Eeceived February 26, 1883.] (Plate XXIII.) I have hesitated whether to consider the following form a distinct species or a variety of Bufo vulgaris. After long consideration, I 1 " O n Ceratodusforsteri," P. Z. S. 1876. |
