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 (SzefioMa maxima) (adult). 



" 2. The Menopoma (adult). 



"3. Siren lacertina (adult and young). 



"4. In the native Newts {Triton cristafus and Lissotriton punc- 

 tatus), 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, AViederslieim, &c.), but never to my satis- 

 ftiction ; 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 Me/iobranchus, 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. 



" We have no such persistently larval forms in the ' Anura ' as we 

 have in this group, where all the forms of the larger and lower 

 ' Proteidea ' can have their counterparts shown in the developing 

 series of the young of any of the higher and smaller (Caducibran- 

 cbiate) 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 Axolot.l 

 (Siredon) and of what can be done in the way of altering the time of 

 metamorphosis in tlie 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- 



