BIRDS. 



333 



Fig. 324. Skull of duck, from Wiedersheim. als, alisphenoid; ag, angulare; 

 apf, foramen palatinum anterius ; ar, articulare ; bo, basioccipital ; bpg, basipterygoid ; 

 bs, basisphenoid ; bi, basitemporal ; d, dentary; en, external nares; et/i, ethmoid ; eo, 

 exoccipital ; eu, Eustachian opening; fin, foramen magnum; fr, frontal; ic, fora- 

 men for internal carotid ; j, jugal ; Ic, lachrymal ; jnx, maxilla ; inxp, palatine 

 process of maxillary; n, nasal; nfx, nasal process of premaxillary ; p, parietal; pg, 

 pterygoid; pi, palatine; pn, posterior nares; ps, presphenoid; px, premaxilla; q, 

 quadrate ; qj, quadratojugal ; so, supraoccipital ; sg, squamosal ; iy, tympanic cavity ; 

 w, vomer ; //, ? ', IX, X, XII, openings for corresponding nerves. 



