34 THE SALAMANDER 



Stadtmiiller, the dentary, during its development, grows round and 

 envelops the larval splenial, which is eventually resorbed, although 

 he thinks that a few of its anterior teeth may occasionally remain 

 fused with the dentary. Thus the bone as above described is 

 equal to the dentary and splenial of Parker's account. Enclosed 

 between the dentary and Meckel's cartilage are branches of nerves 

 V and VII, and the blood-vessels for the nutrition of the teeth, lower 

 lip, &c. 



The pre-artku/ar (o.p-art.) is a wedge-shaped splint of bone which 

 is pushed in between the free edges of the dentary on the mesial side of 

 the jaw. It expands dorsally into a fairly pronounced coronoid pro- 

 cess which is inflected mesially, and thus turns away from the dentary 

 so as to expose Meckel's cartilage and the articular dorsally. It does not 

 become fused with the articular as it does in some forms (e.g. Triton, 

 Gaupp), and is perforated near its posterior end by a foramen for the 

 R. alveolaris of N. VII and the alveolar artery (fo.i.den.). This 

 element represents the arlicu/aroflp2Lrker, and is called the Goniale by 

 Gaupp, Stadtmiiller, and most German authors. 



The Hyobranchial Skeleton. (PI. II, fig. 6 and PI. VI, fig. 38.) 

 In the larval Salamander the hyoid and portions of four branchial 

 arches are all present. In the adult, however, only portions of the 

 hyoid and the first two branchial arches normally persist, the re- 

 mainder disappearing during metamorphosis. The whole skeleton 

 is cartilaginous with the exception of the small os triangulare (q.v.). 



2. The Hyoid (Second Visceral) Arch. 



This arch consists, in the adult, of two elements on either side, 

 namely the hypo- and cerato-hyah. In the larva these two articulate 

 with one another, but in the adult they become separated. The hypo- 

 hyals (c.h.hy.) retain their connexion with the median longitudinal 

 portion of the hyo-branchial apparatus, namely the copula (c.cop.) 

 (or basibranchial^ W^iedersheim), from which they protrude as a pair of 

 short horns pointing in an antero-dorso-lateral direction, being more 

 or less embedded in the substance of the tongue. They are often 

 referred to as the anterior radials of the copula (see below). The 

 cerato-hyals (c.c.hy.) form the anterior cornua of the hyoid. Their 

 anterior ends are greatly expanded into broad spatulate sheets of 

 cartilage which underlie the hypo-hyals ventrally, and also overlap 

 one another in the middle line. Their posterior ends are much 

 narrower and more rounded in section, and curve dorsalwards to 

 about the level of the jaw suspension, where they are attached to the 

 quadrate by a strong elastic ligament, the ligamentum hyo-quadratum. 



