SKULL 



119 



The parietals and frontals are unpaired in the adult, and lacrymals, 

 prefrontals, and postfrontals are present. There is an upper and 

 a lower temporal arcade or zygomatic arch, and between the orbit 

 and temporal fossa is a bony pillar formed by the postfrontal, jugal, 



UK 



FIG. 85. HYOBRAXCHIAL APPARATUS, 

 WITH LARYNX AND TRACHEA, OF 

 Emys turop<:ea. From the dorsal 

 side. 



A A', arytenoid cartilage of larynx ; 

 Cbr.I, Cbr.II, first and second 

 branchial cornua; Chy, hyoid cornu; 

 P./, lingual process; UK, cricoid 

 cartilage of larynx ; Tr, trachea ; 

 ZB, broader anterior, and ZK, nar- 

 rower posterior part of basihyo- 

 branchial. 



Coec 



FIG. 86. SKULL, OF A YOUNG 

 CROCODILE. Ventral view. 



Ch, internal nostrils ; Cocc, oc- 

 cipital condyles ; Jy, jugal ; 

 J/, palatine process of max- 

 illa ; Ob, basioccipital ; Orb, 

 orbit ; PI, palatine ; Pmx, 

 premaxilla ; Pt, pterygoid ; 

 Qj, paraquadrate ( ' ' quadrato- 

 jugal") ; Qu, quadrate ; Ts, 

 transpalatine. 



and transpalatine : the vomer is paired. The palatines and ptery- 

 goids are very firmly attached to the base of the skull, and both 

 these bones, as well as the paired premaxillae and maxillae, take 

 part in the formation of the hard palate. 1 Thus the internal 

 nostrils open far back, beneath the basioccipital, from which alone 

 the occipital condyle is formed. The exoccipitals meet above the 

 foramen magnum, thus shutting out the supraoceipital. Teeth are 

 present in sockets on the premaxillae, maxillae, and dentaries. 



A series of air-passages extends into the bones from the 



1 In the pre-Cretaceous Crocodiles the pterygoids did not form palatal 



plates. 



