THE SKULL. 



233 



mal is pre- 

 sent -at the 

 anterior 

 margin of 

 the orbit. 

 The eth- 

 moid re- 

 gion and 

 the cranial 

 capsule are widely separated by an in- 

 terobital septum of considerable size. 

 The latter, sometimes together with the 

 remains of the fused orbitosphenoids, 

 frequently remains membranous and 

 unossified in its median part, and rests 

 on an elongated bony rod corresponding 

 to the basisphenoid. At the base of the 

 temporal region there are two bones 

 basitemporals (Parker) which are 

 ankylosed with one another, and are 

 probably to be referred to a parasphe- 

 noid. In all cases independent alisphe- 

 noids are present. The ethmoid region 

 is composed of a vertically placed, un- 

 paired ethmoid, situated in the anterior 

 prolongation of the interorbital septum, 

 and of lateral ethmoids which separate 

 the eyes and nasal cavities, and through 

 which the olfactory nerves pass into the 

 nasal cavities. The lateral ethmoids may 

 be swollen and contain ethmoidal cells. 

 In front of them are developed the two 

 nasal cavities with their bony or carti- 

 laginous septum, which is the prolonga- 

 tion of the unpaired ethmoid, and affords 

 a support to the rolled -up turbinal bones, 

 which are sometimes also attached to the 

 vomer. The facial bones unite to form 

 a projecting beak, the margins of which 

 are covered with horny substance, and 

 which is often movably connected with the 



Jmx 



Me 



Vo 



Pa 



FIG. 648. Skull of Otis tarda (bust- 

 ard), a, From the side ; 6, from 

 beneath. Ob, basi-occipital ; C, 

 condyle; 01, ex-occipital; Os, 

 supra-occipital; Sq, squamosal; 

 Et, basi-temporal(parasphenoid); 

 Spb, basi-sphenoid ; Als, ali- 

 sphenoid; Sm, inter-orbital sep- 

 tum ; Et, median ethmoid ; Pa, 

 parietal ; Fr, frontal ; MX, maxil- 

 lary ; Jmx, prsemaxillary ; -ZV, 

 nasal ; L, lachrymal ; J, jugal ; 

 Qj, quadrato-jugal ; Q, quadrate ; 

 Ft, pterygoid ; Pal, palatine ; Va, 

 vomer; -D, dentary; Art, articu- 

 lare ; Ang, angulare. 



skull. The suspensorium 



