II 



SKULL 



A pair of prefrontal lioues is present in most Salaniaiidridae, 

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

 in Cryptohranclms ; these bones are absent in AmplUumn , jVecfurus, 

 Proteus, and Siren. 



The laerymalia are still separate in some Amblystomatinae, 



Fig. 3. — Skulls of various 

 Urodela. 1, Salamandra ma- 

 cnlosa, ventral view, and 2, 

 dorsal view ; 3, Axolotl stage of 

 Aviblystoma ; 4, adult stage of 

 Amblystmna ; 5, Salamandrina 

 perspicillata (after Wieders- 

 lieim) ; 6. Salamandra ma- 

 culosa, dorsal view of the lower 

 jaw. ,1, Articulare ; Cj, C.,, 

 outer and inner occipital con- 

 dyles ; Ch, clioana or posterior 

 nasal opening ; d, dentary ; E, 

 ethmoid ; F, frontal ; LO, 

 lateral occipital ; M, maxillary ; 

 JV, nasal ; ^Y(9,nostril ; OS, orbito- 

 sphenoid ; P, parietal ; Pf, pre- 

 frontal ; PI, palatine ; Pm, pre- 

 maxillary ; Po, prootic ; PS, 

 parasphenoid; P<, pterygoid ; Q, 

 quadrate ; S, angulo-sjdeuial ; 

 Sr/, squamosal ; St, stapes ; Vn, 

 vomer; IL VII, X, exits of the 

 optic, facial, and glosso- vagus 

 nerves. 



e.g. lianidens and Hynohiioi. A pair of nasalia are generally 

 ]iresent, but are absent in Xecturus, Proteus, and Siren. The 

 ] )arasphenoid is furnished with teeth in the Plethodontinae and 

 Desmognathinae. 



Separate palatine bones exist in Necturas and J'rulcuti, and in 

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

 the vomers, producing the vomero-palatiues characteriRtio of the 

 majority of Urodela. 



VOL. \i\i c 



