872 



SKULL 



unpaired Prpesphenoid, forming with it the rostrum of the basis 

 cranii ; (3) the Vomer, paired or impaired, resting upon the septum. 

 V. Bones derived from, or developed upon, visceral arches, form- 

 ing the appendicular apparatus of the Skull — (1) the unpaired 



Pmx. 



Analytical Diagram of a Bird's Skull. 



Prsemaxilla ; (2) the right and left MaxillaB ; (3, 4, 5) the right 

 and left " Palatines," Pterygoids and Quadrates — these being, as Avell 

 as (6, 7) the right and left Jugals and Quadrato-jugals, modifica- 

 tions of the dorsal half of the first visceral arch ; (8) the bones 

 forming the right and left Mandibulfe (or the lower jaw) — namely, 

 the Dentals, Sj)lenials, Supra-angulars, Angulars and Articulars — all 

 these last being modifications of the ventral half of the same (first) 

 visceral arch; (9) the ossicles of the ear, columella auris (p. 179), 



'C.Br. ; 



■Br. Ill 



Analytical Diagram of thf. Visceral Arches. The dotted portions are not deYeloped. 



being the remnants of the dorsal half of the second Adsceral arch 

 ( = the 1st branchial arch), while the remnant of its ventral half 

 is transformed into the os entoglossuni (p. 453) ; (10) the rest of the 

 Hyoid apparatus formed by the third \dsceral ( = 2nd branchial) 

 arch. 



