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Show 102 MR. P. E. BEDDARD ON THE [Feb. 6, tail with a broad membranaceous fin continued to the end of the tail "-implying the absence of a dorsal fin. The next description and figures of the tadpole are to be found in the late M r . W . K. Parker's memoir upon the Batrachian skull1. The dorsal and ventral aspects of the larva (loc. cit. pi. 56. figs. 1, 2) are very much better than the lateral view (he. cit. pi. 56. fig. 3) which has been copied into the textbooks. This lateral view exaggerates the fishlike build of the larva, and even suggests armoured and extinct fishes. The dorsal and ventral fins, both of which are shown, are depicted as ceasing abruptly some way in front of the end of the tail, giving to it a totally undeserved " Chimaeroid " look. There are, however, in the paper to which I refer some valuable notes upon the external characters of the tadpoles, as well as (of course) upon the skull-structure. The tentacles are correctly described, the absence of horny teeth noted, and the paired branchial orifices correctly located. On the other hand, as I shall show in the present paper, Prof. Parker was wrong in stating the absence of claspers beneath the chin. Quite recently2 Mr. Leslie has still further increased our knowledge of this Amphibian, though his notes Math regard to the larva are only confirmatory of the results given in Parker's paper and are not wholly accurate, as I shall point out later, in the alleged absence of external gills. The eggs laid in the Society's Gardens were deposited singly; no great masses of spawn like those of our Common Prog were found. Nevertheless I had a group of four or five adherent eggs brought to me. The eggs were laid some time in the evening of Saturday, M a y 27th, 1893 ; by Monday morning at 10 A.M. I had newly-hatched larvae. The intervening Sunday prevented m e from examining into the early stages of development. The rapidity with which the larvae were hatched out is remarkable. At the Cape the breeding-season is early spring (August), but Mr. Leslie does not mention the period of time which elapses between the deposition of the ova and the appearance of tadpoles. The specimens which bred at the Gardens were some which Mr. Finn brought back with him from Zanzibar. External Form and Colour.-The most remarkable point about these tadpoles is their extreme transparency. As will be seen from the accompanying drawings (Plate XIII.), the pigment is thinly scattered about, not obscuring the internal structure. The bloodvessels and even the nerves can be readily detected when the tadpole is examined alive. At first the tadpoles are in shape like those of the C o m m o n Frog; but on the third day, as M r . Leslie correctly observes, the characteristic form of the more mature tadpole is acquired. The head and body become broader, and are not separated by a constriction as they are in the Common Frog. In 1 « On the Structure and Development of the Skull in the Batrachia, Pt. II.," Phil. Trans, vol. 166 (1877), p. 625. 3 " Notes on the Habits and Oviposition of Xenopus Iceins, P. Z. S. 1890, p. 69. |
