350 



ZOOLOGY 



SECT. XIII 



In the Chelonia (Figs. 991, 992) all the bones, inchiding the 

 quadrate, are solidly connected together. Transverse bones 

 (ectopterygoids), lacrymals, orbitosphenoids and alispheuoids are 

 absent. The place of alisphenoids is taken to a certain extent 

 by vertical downward plate-like extensions of the parietals, the 



Pmx 



Fig. 990.— Skull of Sphenodon. A, Dorsal ; B, ventral ; 0, lett-sided view of skull of 

 Sphenodon, x(i. Coi. Columella auri.s ; Ctmd. occipital condyle; E. P. ectopterygoid ; 

 /''. frontal ; Jug. jugal ; Max. maxilla ; Na. nasal ; Nc. anterior nasal opening ; Pal. 

 palatine; Par. parietal; P7i?.i:. premaxilla ; Prf. prefrontal; Pt.f. post-frontal and post- 

 orbital ; P(<7. pterygoid or ondoptfrygoid ; Q. quadrate and quadra'to-jugal ; Sg. squamosal ; 

 Fo. vomer. (From the Cambridge Natural History.) 



lower part of the plates representing the epipterygoids of 

 Lizards. There may be open temporal fossse, the inferior boundary 

 of which {inferior temporal arch) may be incomplete owing 

 to the absence of the quadrato-jugal, or the entire temporal 

 region may be covered over (Turtles, Fig. 992) by a sort of false 



