SKULL 



17 



A pair of prefrontal bones is present in most Salamandridae, 

 e.g. Salamandra, Triton, Arably stoma, especially in the larva, and 

 in Cryptohranchus ; these bones are absent in Amphiicma, Necti(,rus, 

 Proteus, and Siren. 



The lacrymalia are still separate in some Amblystomatinae, 



Fig. 3. — Skulls of variou.s 

 Urodela. 1, Salamandra ma- 

 culosa, ventral view, and 2, 

 dorsal view ; 3, Axolotl stage of 

 AmUystoma ; 4, adult stage of 

 Amblystoma ; 5, Salamandrina 

 perspicillata (after Wieders- 

 lieim) ; 6, Salamandra ma- 

 ciUosa, dorsal view of the lower 

 jaw. A, Articulare ; Cj, Gj, 

 outer and inner occipital con- 

 dyles ; Ch, choana or posterior 

 nasal opening ; d, dentary ; Ji, 

 ethmoid ; F, frontal ; LO, 

 lateral occipital ; M, maxillary ; 

 iV, nasal ; iK),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 ; >S'^, stapes ; Vo, 

 vomer ; II, VII, X, exits of the 

 optic, facial, and glosso- vagus 

 nerves. 



e.g. Banidens and HynoUus. A pair of nasalia are generally 

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

 ]iarasphenoid is' furnished with teeth in the Plethodontinae and 

 Desmognathinae. 



Separate palatine bones exist in Necturus and Proteus, and in 

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

 the vomers, producing the vomero-palatiues characteristic of the 

 majority of Urodela. 



VOL. VIII ^ 



