SKELETON. 



66 J 



maxilla, jugal and quadrato-jugai, the last abutting on the 

 movable quadrate. 



Ot the membrane 

 bones on the side of the 

 skull, the lachrymal in 

 front of the orbit, and 

 the squamosal between 

 the quadrate and the 

 parietal, are the most 

 important. 



On the roof of the 

 mouth, the basisphenoid, 

 which lies just in front 

 of the basioccipital, is 

 covered over by a mem- 

 brane bone the basi- 

 temporal. In front of 

 this is a sharp "basi- 

 sphenoid rostrum " or 



parasphenoid, also a - ^// // // 1///3 Nf \\ \\ \^pa- 

 membrane bone. Artic- 

 ulating with the quadrate 

 and with the rostrum 



are the pterygoids; in // JwiJ-dil Jk^Pt 



front of these lie the 

 palatines. The vomer 

 is vestigial. The bony 

 front of the palate is 

 formed from inward ex- 

 tensions of the 'pre- 

 maxillae and maxillae. 

 The interorbital septum 



, FIG. 364. Under surface of gull's 

 the mesethmoid, but also skull. From Royal Scottish Museum, 

 from the presphenoid. Edinburgh. 



From the tympanum tO c., Condyle; b.t., basitemporal ; 6.S., basi- 

 fViP inn^r par PvfpnrU the sphenoidal rostrum; //., pterygoid ; /a., 



palatine ; ., yomer ; /. mx.> premaxilla; mx., 

 rod-like COlumella. The maxilla; /., jugal; f./, quadrato-jugal ; q., 



lower jaw originally con- qua< 



sists of four membrane bones dentary, splenial, angular, and 



surangular; and one cartilage bone the articular. The 



