SKULL. 



427 



postorbital process of the frontal. There are no prefrontals, 

 postfrontals, or postorbitals, and the orbit is not closed pos- 

 teriorly from the temporal fossa, though in parrots the post- 

 orbital process of the frontal meets a backwardly directed 

 process of the lacrymal beneath the orbit. 



FlO. 237. Skull of Otis tarda (bustard), a from the 

 side ; b from below (from C'laus). Ah alispheuoid ; 

 Ang auaular ; Art articular ; Bt basitemporal (para- 

 sphenoid) ; C occipital condyle ; D dentary ; FA 

 median ethmoid ; fr frontal ; J jugal ; Jma; premaxilla ; 

 L lacrymal ; Mz maxilla ; N nasal ; Ob basioccipital ; 

 01 exoccipital ; Os supra-occipital : Pa parietal ; Pal 

 palatine ; Pt pterygoid ; Q quadrate ; Qj quadrato-ju- 

 gal ; Sm interorbital septum ; Spb basisphenoid ; Sq 

 squamosal ; Vo vomer. 



The squamosal {Sq) is closely applied 

 to the skull and is ankylosed with the 

 periotic bones (pro-, epi-, and opis- 

 thotic) ; it often sends a process down- 

 wards over the quadrate bone. There 

 are no parotic processes. The quad- 

 rate is moveably articulated with the 

 squamosal, the prootic and the alisphe- 

 noid. The palate is very imperfect, 

 the posterior nares are between the 

 palatines and the vomer which is 

 usually much reduced, and the maxil- 

 laries usually have a maxillo-palatine 

 process {Mx). There is no second- 

 ary hard palate. The occipital condyle is single and 

 there is no parietal foramen. Parasphenoidal elements are 

 present in the form of the basitemporals which are fused with 

 the base of the skull and as the basisphenoidal rostrum. The 

 eustachian tubes are included in the basisphenoid and the aper- 



