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Show 544 MR. PARKER ON THE SKULL OF BATRACHIANS. [Nov. 16, Mr. W. K. Parker read the following abstract of a memoir on the development of the skull in the Urodele Batrachians. " In the present paper I have worked out the skulls of:- " 1 . The Giant Salamander (Sieboldia maxima) (adult). " 2. The Menopoma (adult). "3. Siren lacertina (adult and young). " 4 . In the native Newts (Triton cristatus and Lissotriton punctatus), several stages, including the adult. "These latter I have found to be extremely instructive, as they show in their various stages that which is permanent in the skulls of the larger but lower types. " The skull of the Great Salamander has been figured before (by Temminck and Schlegel, Wiedersbeim, & c ) , but never to my satisfaction ; and the specimen which lived so long in the Gardens of the Society was evidently larger and older than those dissected and figured by the authorities above mentioned. The types of Urodeles worked out by Wiedersheim and me are now very numerous ; and if any one curious in such matters will read and compare what we have written and illustrated, I am confident that he will find that this field has been cultivated, relatively to its extent, as carefully and as neatly as any that can be mentioned. "But Prof. Huxley's paper on Menobranchus, published in the Proceedings of the Society in 1874 (March 17), remains for all time the model ' headland' for all such husbandry: to it, and to the more general account of the Urodeles in his article on the Amphibia in the new edition of the ' Encyclopaedia Britannica,' I am greatly indebted. " I am satisfied that this group is extremely well worth all the labour that has been spent upon it, from time to time, by many workers, and that there is in it still much land to be possessed. " W e have no such persistently larval forms in the ' Auura ' as we have in this group, where all the forms of the larger and lower ' Protei'dea' can have their counterparts shown in the developing series of the young of any of the higher and smaller (Caducibran-chiate) types. " The indefiniteness of the boundary line between the Proteidea and the Salamandroids is of extreme interest; and this is heightened by the well-known facts of the variable metamorphosis of the Axolotl (Siredon) and of what can be done in the way of altering the time of metamorphosis in the viviparous Salamander, which, as a rule, absorbs its gill-tufts before it is born. " Morphologically, the interest of this group is unsurpassable ; here for the first time we meet with the rudiments of structures that go on unto perfection in the ascending scale of types. " Amongst these I may mention the cartilaginous larynx, and the stapes and columella (the outworks of the ear), the latter being formed of a half-aborted or arrested or partly absorbed element that belongs to the hyoid arch. "In these forms we see the very simple bony plates and cartilages of the larva that correspond with what we find in those very genera- |
