SKULL 



A pair of prefrontal bones is present in most Salamandridae, 

 e.g. Salamandra, Triton, Amblystoma, especially in the larva, and 

 in Cryptobranchus ; these bones are absent in AmpJiiuma, Necturus, 

 Proteus, and Siren. 



The lacrymalia are still separate in some Amblystomatinae, 



FIG. 3. Skulls of various 

 Urodela. 1, Salamandra ma- 

 culosa, ventral view, and 2, 

 dorsal view ; 3, Axolotl stage of 

 Amblystoma ; 4, adult stage of 

 Amblystoma; 5, Salamandrina 

 perspicillata (after Wieders- 

 heim) ; 6, Salamandra ma- 

 culosa, dorsal view of the lower 

 jaw. A, Articulare ; C lt (7 2 , 

 outer and inner occipital con- 

 clyles ; Ch, choana or posterior 

 nasal opening ; d, dentary ; E, 

 ethmoid ; F, frontal ; LO, 

 lateral occipital ; M, maxillary ; 

 N, nasal ; .2V0,nostril ; OS, orbito- 

 sphenoid ; P, parietal ; Pf, pre- 

 frontal ; PI, palatine ; Pm, pre- 

 maxillary ; Po, prootic ; PS, 

 parasphenoid; P, pterygoid ; Q, 

 quadrate ; S, angulo-splenial ; 

 Sq< squamosal ; St, stapes ; Vo, 

 vomer ; II, VII, X, exits of the 

 optic, facial, and glosso- vagus 

 nerves. 



e.g. Eanidens and Hynolius. A pair of nasalia are generally 

 present, but are absent in Necturus, Proteus, and Siren. The 

 parasphenoid is furnished with teeth in the Plethodontinae and 

 Desmognathinae. 



Separate palatine bones exist in Necturus and Proteus, and in 

 the larva of AmUystoma, but in the adult form they fuse with 

 the vomers, producing the vomero-palatines characteristic of the 

 majority of Urodela. 



VOL. VIII C 



