THE SKULL. 



71 



Pnr To I\' 



Yir,. 56. SKULL OF A YOUNG 

 AXULOTL. (Ventral view.) 



J/ 



Ceec Osp 



FIG. 57. SKULL OF Salamandra atra 

 (ADULT.) (Dorsal view.) 



a 



-Can 



111 



on 



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

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

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

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

 f>sp, dorsal tract of the occipital cartilage ; AV, internasal plate, which extends 

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

 XfC, nasal capsule : Can, nasal cavity ; 3~a, external nostrils ; tl. foramen for the 

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

 plate, which forms a roof for the iuternasal cavity (Fig. 57) ; Qu, quadrate ; Ptc, 

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

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

 7V, palatine ; Pp, palatine process of maxilla ; Vop, vomero-palatine ; Pmx, 

 premaxilla : M, maxilla ; Os, sphenethmoid ; As, prootic ; .iV, nasal ; Pf, pre- 

 froutal, perforated at D for the lacrymal duct ; F, frontal ; P, parietal ; Sqti, 

 s]uamosal ; II, optic, J". trigeminal, and VII, facial foramen ; ?, point of 

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



