BIRDS. 



333 



S.O 



ar 



7** 



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

 amen palatinum anterius ; ar, articulare ; bo, basioccipital ; bpg, basipterygoid ; 

 A;, basisphenoid ; bt, basitemporal ; d, dentary ; en, external nares; eth, ethmoid ; eo, 

 exoccipital ; en, Eustachian opening; fm, foramen magnum; fr, frontal; ic, fora- 

 men for internal carotid; /, jugal ; Ic, lachrymal; mx, maxilla; ttixp, palatine 

 - of maxillary; n, nasal; npx, nasal process of premaxillary ; /, parietal : /^, 

 id; //, palatine; pn, posterior nares ; fs, presphenoid ; px, premaxilla; q, 

 quadrate; yj, quadratojugal ; 5t>, supraoccipital ; sq, squamosal ; ty, tympanic cavity ; 

 v, vomer ; //, V, IX, X, XII, openings for corresponding nerves. 



