THE SKULL. 



71 



Pm.r To S. 



Fa, 



Cvcc 



Fin. 56. SKULL OF A YOUNG 

 .AxuLOTL. (Ventral view. ) 



T, 



face Osp 



FIG. 57. SKULL OF Salamandra atra 

 (ADULT.) (Dorsal view.) 



ft 



fore 



FIG. 58. SKULL OF Salamandra atra (ADULT). (Ventral view.) 



Irabecula ; OB, auditory capsule ; For, fenestra ovalis, closed on one side by 

 the stapes (St) ; Lett, ligament between the stapes and suspensorium ; Cocc, occi- 

 pital condyles ; Bp, cartilaginous basilar plate between the auditory capsules ; 

 Osp, dorsal tract of the occipital cartilage ; IN, internasal plate, which extends 

 laterally to form processes (TF and AF) bounding the posterior nostrils (Ch); 

 NK, nasal capsule ; Can, nasal cavity ; Na, external nostrils ; 1*1, foramen for the 

 olfactory nerve ; Z, tongue-like outgrowth (intertrabecula) of the internasal 

 plate, which forms a roof for the internasal cavity (Fig. 57) ; Qti-, quadrate ; Ptc, 

 cartilaginous pterygoid ; Pot, otic process, ped, pedicle, and Pa, ascending 

 process, of the quadrate ; Ps, parasphenoid ; Pt, bony pterygoid ; Vo, vomer ; 

 PI, palatine ; Pp, palatine process of maxilla ; I'op, vomero-palatine ; Pni->\ 

 prcmaxilla ; M, maxilla ; Os, sphenethmoid ; As, prooiic ; N, nasal ; Pf, pre- 

 frontal, perforated at D for the lacrymal duct ; F, frontal ; P, parietal ; 8qu, 

 squamosal ; //, optic, V, trigrminal, and VII, facial foramen ; II', point of 

 entrance of the nasal branch of the fifth nerve into the nasal capsule. 



