IV 



GENERAL ANATOMY 



85 



also in tlie otlier Lissaiupliibiu, while supratemporals and supia- 

 oecipitals are absent. There is, however, a pair of bones wliioh 

 represent either the postorl)itals or the postfrontals, perhaps 

 both, of the Stegocephali. The quadrato-jugal arch is enormously 

 developed, and by reaching the parietal, frontal, and postorbito- 

 frontal bones (which latter occur only in fchtliyophis and 

 Uraeotjiphhis) and the maxilla, extends over the wliole of the 

 orbito-temporal fossa. Tlie squamosal is completely fused with 



Fig. Wi.—'A'kwWai THi thy o})Ms(jlutinosa. x 3. (After Sarasin.) A, Lateral, B, ventral, 

 C, dorsal view. A, Posterior jirocess of the os articnlare ; C'a, carotid foraiueii ; Cli, 

 clioana or po.sterior nasal opening ; F, frontal ; ./, jugal ; Lo, lateral occipital ; 

 Mx, maxillary ; X, nasal ; No, nostril ; 0, orbit ; I', parietal ; Pa, palatine ; Pm, 

 premaxillary '; Pof, jiostfrontal ; Prf, prefrontal ; Pt, pterygoid ; Q, quadrate ; A', 

 squamosal ; SI, stapes ; T, tentacular groove ; I'o, vomer ; A', exit of vagus nerve. 



the (luadrato-jugal. The stapes lias the typical stirrup-shape, is 

 even perforated by an artery, and articulates distally with the 

 shaft of the quadrate (as in the snakes). The maxilla is very 

 large and broad. Owing to its broad junction with the quadrato- 

 jugal arch, the prefrontal and frontal, the orbital fossa is reduced 

 to a very small hole, or the maxilla completely covers the eye. 

 Somewhere between the latter and the nares tlie maxilla is 

 perforated Ijy the tentacular groove. The periotic bones are 

 represented by the prootics and ejjiotics ; they fuse with 

 the lateral oceipitals and witli the ])ara.sphenoid. The whole 



