COM PARATIVK ANATOMY 



sphenoids, and the ethmoids, are the four groups constituting the car- 

 tilaginous cranium. (Compare Figs. 407, 409, 410, 411, 412, 413, 414.) 



Fig. 411. 



Upper two views, skull of snake, an, angulare ; av, articular ; bo, basioccipital : 

 bs, basisphenoid ; d, dentary ; eo, exoccipital ; epo, epiotic ; /, frontal ; mx, 

 maxillary ; n, nasal ; oo, opisthotic ; p, parietal ; pi, palatine ; pm, premaxillary ; 

 pro, prootic ; pa, parasphenoid ; pt, pterygoid ; q, quadrate ; sa, surangulare ; so, 

 supraoccipital, sq, squamosal ; tr, transversum. ( From Kingsley after W. K. 

 Parker.) 



Lower two views, skull of turtle. A, lateral view. B, from below, ang. 

 angulare, art, articulare ; au, orbit ; b.sph., basisphenoid ; ch, choanae ; d, dentary ; 

 fr, frontal ; j, jugular ; max, maxillae ; occ.b, basi-occipital ; occ.L, lateral occipital ; 

 occ.s., superior occipital ; op.ot., opisthotic ; pal, palatine ; par, parietal ; p.fr., 

 postfrontal ; pr.mx., premaxillae ; pr.fr., prefrontal ; pt, pterygoid ; q, quadrate ; 

 q.j., quadratojugal ; sq, squamosal; vom, vomer. (After Schimkewitsch.) 



