GENERAL VIEW OF THE SKULL. 



39 



archy which is semi-elliptical in form, aud marks the entrance to 

 a large cavity above called the nasal chamber ; this cavity is in 

 the fresh state, divided into right and left compartments or fossae 

 by a cartilaginous septum. 



Between the posterior molars and the palatine arch are the 

 two palatine foramina. Behind, and 

 bounded by the palatine arch, are the 

 entr:?.nc£3 to the nasr.l chamber, right 

 <r.nd left, called ths posterior nares, 

 t:D.d. ths c-lender median bone stretch- 

 ing from behind forwards in the cavity 

 is the vomer ; it indicates the division 

 of the chamber into right and left 

 ioszcd. Continuous with the vomer 

 WG find an irregular column of bone 

 reaching to the back of the skull; 

 thi3 column consists cf three pieces, 

 xh.Q pre-cphenoid anteriorly, then the 

 basi-sphenoid, and lastly the basi- 

 occipital bone. These bones are 

 respectively parts of the sphenoid and 

 occipital bones, and they, together 

 with the vomer, are regarded as the 

 centra of the cranial vertehrce ; and 

 the ossified suture between tho last 

 tv/o bones is usually marked by a 

 roughened ridge. 



On the posterior edges of the pala- 

 tine arch are i'::o small sharp projec- 

 tions, the ends cf the pterygoid bones, 

 and behind them the rough palatine 

 ridges, the posterior edges of which 

 are formed by the pterygoid processes 

 cf the sphenoid bone ; outside the 

 base of each of these processes we 

 have the posterior aperture of the 

 cuhsphenoidal or pterygoid forarn^en, which gives passage to 

 an important artery. There are tv/o large, rounded, and may be 

 roughened prominences, the alveob^r tuberosities, immediately 

 behind the last molar teeth, and between them and the palatine 

 ridges and pterygoid bones are the smooth staphyline grooves^ 



Fig. 11. 

 luferior aspect of Eorse's Ekull, 

 the mandible being removed. Above 

 the line A iz the posierior region or 

 hme, between A and B the middle, 

 and below B the anterior or nasal 

 region, a. Occipital CDnd3^ie ; &, Fora- 

 men magnum : c, Styloid process ; 

 d, Temporal rrticular siirfac3 ; e, Basi- 

 occipital, and/, Basi-sphoncid bones ; 

 a, Petrosal bone ; h, All - sphenoid 

 bone : i, Temporal bone ; fc. Condyloid 

 foramen ; fc' Condyloid notch ; I, Fora- 

 men lacerum basis cranii ; n. Ptery- 

 goid foramen ; «, Paiatire suture ; 

 0, Palatine foramen ; p, Molar teeth ; 

 q, Incisive opening ; r, Forameu 

 incisivum. 



