2 8 THE SALAMANDER 



(c) The pars palatina is a narrow but strong bar of bone which helps 

 to form the osseous palate. According to Stadtmiiller it arises partly 

 by the fusion of tooth sockets and partly as a separate ossification direct 

 from the membrane. 



The maxillae (o.m.) complete the arch of the upper jaw and sur- 

 round the latero-ventral edge of the cartilaginous nasal capsule like 

 a gutter. Like the pre-maxillae each bone has three parts : (a) The 

 pars facialis borders the postero-lateral margin of the external nasal 

 aperture and covers the side of the face as far as the antero-lateral 

 angle of the orbit. Dorsally it extends on to the edge of the nasal, 

 and ventrally it fuses with (b) the pars dentalis which, like the corre- 

 sponding part of the pre-maxilla, arises by the fusion of tooth-sockets. 

 The teeth only extend backwards to about the level of the anterior 

 margin of the optic fenestra. (<:) The pars palatina corresponds en- 

 tirely with the similarly named portion of the pre-maxilla, against 

 which it abuts anteriorly. On the mesial side it meets the pre-vomer. 

 The maxilla extends posteriorly to about the level of the hinder 

 border of the optic fenestra. Its posterior extremity lies lateral, and 

 slightly caudal, to the anterior extremity of the pterygoid, and is 

 joined to the lateral extremity of the suspensorium by a pair of tough 

 ligaments — tho. jugal ligaments — but there is no bony connexion as in 

 the Frog. 



The nasals (o.nas.) are paired bones of a rather irregular shape 

 serving to roof over the mesial portion of the nasal capsules. Their 

 antero-lateral edges curve round the mesial border of the external 

 nasal aperture.^ Mesially they meet, and overlie, the antero-lateral 

 edges of the frontals and the pre-nasal processes of the pre-maxillae, 

 while posteriorly they adjoin the pre-frontals, and laterally meet the 

 dorsal edges of the facial portions of the maxillae, and are slightly 

 covered by them. The nasals are distinctly lateral in position and 

 are widely separated from one another in the middle line. They are 

 perforated by a variable number of foramina for the passage of the 

 ultimate twigs of the mesial branch of the N. ophthalmicus profundus 

 V. According to Stadtmuller their development is relatively late. 



ThQ pre-frontals (o.p-fr.) {fronto-lacrymaux^ Duges; ectethmoid V^iV- 

 ker) are also paired and occur on each side of the skull immediately 

 anterior to the orbit. They are more or less quadrangular in shape, 

 and are comparatively small. Their anterior borders are covered by 

 the nasals, mesially they overlie the edges of the frontals, while 

 laterally they are in turn pushed under the dorsal edges of the facial 



' It should be noted that the aperture formed by the edges of the pre-maxillary, 

 maxillary, and nasal bones is larger than the actual cutaneous opening. 



