THE SKULL IN THE CHAMELEOXS. 99 



The Endocranium of the Bioarf Chameleon. 



The endocranium, on the whole, is quite like that of the last kind. The occipital 

 condyle {oc. c) is large and projecting ; it is suboval, with its long diameter transverse. 

 The basioccipital {b.o) is hollow beneath, projects externally, and is widest in front. 

 The exoccipitals (6;.o) are confluent with the opisthotics(t)/;) ; but the nerve-pa-ssages (ix, 

 x) are their landmarks. So, also, the supraoccipital {s.o) is confluent with the epiotic ; 

 it sends up a much smaller crest to meet the less-modified interparietal region. The 

 foramen magnum (fig. 4, f. m) is pyriform ; it is much elongated upwards. The parotic 

 processes (o^j)are much shorter than in C. vulgaris; the posterior canal (p.s.c) is seen 

 to be largely imbedded in the opisthotic ; its upper part, which passes into the tube of 

 the anterior canal (fig. 5, a. s. c, p. s. c), lies in the epiotic (e/j). 



The prootic (fig. 5, pr.o) contains most of the anterior and horizontal canals (h. s. c) ; and 

 the side view shows the M'hole occipito-otic region to be very limited, and shaped like 

 an hourglass. 



A lanceolate space, nearly as large as the combined occipital and periotic regions, lies 

 in front of them, naked of cartilage and of bone (al.s.f). The oblique band of cartilage 

 passing in front of this " fenestra," and leaning forwards, is the alisphenoid (al.s) ; two 

 thirds of its lower half is ossified as a shaft-bone ; below it is continuous with the basi- 

 sphenoid, and in front, at the middle, with the orbito- and presphenoid. The roof- 

 bone ( i.])) rests upon its somewhat dilated top. The basisphenoid (figs. 2, 4, & 5, h.s) is 

 a large two-winged bone, narrowing from before backwards, crescentically emarginate 

 behind, and bifid in front ; it has- large, dilated, descending basipterygoid wings {h.pg), 

 and above is scooped for the pituitary body. This bone articulates with the basi- 

 occipital behind, the prootics at its sides, and the small parasphenoid in iront. 



There is a triangular notch between the ali- and orbito-sphenoids, a large common 

 optic passage (ii), and an oblique pyriform interorbital fenestra (i.o.f), as in the 

 Common kind and in many other of the Lacertiiia. The orbito-sphenoid wings (o.s) are 

 not large ; the common orbito-nasal septum {p.s,^). e) rapidly lessens forwards ; there is 

 no definite bony tract in front of the optic passage. 



Tlie Inferior Arches of the Dwarf Chameleon. 

 These parts are very similar to what I have described in the Common species. The 

 quadrate [q) has a definite otic process and pedicle {ot.p,pd); the articulare {ar) is 

 well ossified ; and the postmandibular arches, like the mandible itself, are a mere 

 miniature of what is to be seen in the Common kind. 



CoMPAKisox of the Skull of the Chameleon with that of other Lacektill\, especially 



the typical Lacerta. 

 Leaving out the Chameleon, the types whose skulls are most unlike are Lacerta and 



