78 ORGANS OF SUPPORT, 



the bodies of the vertebrae, and by forming a small arch 

 they give protection to the large blood-vessels of the tail, 

 which is generally a thick muscular continuation of the 

 trunk. There are false ribs in front of the true, as well as 

 behind them, as we see also in birds, and in some mam- 

 malia ; and there are generally about seven cervical vertebrae, 

 as in quadrupeds. The head is extended forwards in the 

 same straight line with the vertebral column, as in the 

 inferior vertebrated classes. As in these inferior classes 

 also we observe the bones of the head of the lacertine rep- 

 tiles remarkably loose and moveable in their articulations, 

 as seen in this figure of the skull of the lacerta nilotica, 

 Cuv. (Fig. 40.) The occipital bone, as in the serpents, has 

 its transversely elongated condyle composed chiefly of the 

 basilar portion of that bone. Exterior to the two condyloid 



pieces, (g, a,) of the oc- 



. ., i ^11 i FIG. 40. 



cipital are the long slen- 

 der, curved, squamous 

 (/,) and mastoid (m } ) ele- 

 ments of the temporal 

 bone, almost as loose as 

 in serpents, and giving 

 support to the short and 

 moveable tympanic por- 

 tion (r,) of that bone to which the articular portion of the 

 lower jaw is attached. The two parietals (n,) are anchylosed 

 together, as in serpents, and support the posterior edges of 

 the two middle frontals (c, c.) The anterior (e, e,) and the 

 posterior (i, i,) frontals form the upper boundary of the 

 large bird-like orbits. The petrous portion (p 9 p 9 ) of the 

 temporal bone is here the largest and strongest element, 

 extending forwards to the sphenoid (s s ) and backwards to 

 the very long and slender squamous (/,) and mastoid (m,) 

 portions. The two lachrymal bones (/,/,) extend less over 

 the face than in serpents, and between them and the an- 

 terior frontals (e, e 9 ) are the superciliary bones (h, h } ) as in 

 birds. The upper jaw bones (d, d,) and the intermaxillaries 

 (a,) are more fixed than in the former order of reptiles, and 

 these intermaxillaries are often anchylosed together, as are 

 also the two narrow lengthened nasal bones (b.) The large 

 inferior turbinated bones are here exposed, from the small- 



