CROCODILIANS, LIZARDS, AND SNAKES. 211 



changeable hue of their skin, first noticed in them, is a i)eciili:irity shared 1)y many 

 other lizards, and to an equal if not stronger degree by Calotcs. 



About one-half of the species occur in Madagascar and neighboring islan<ls, the 

 other half in Africa; the common Chani;eIeon is Mediterranean, occurring in Europe, 

 however, only in Andalusia; a species inhal)its Socotra, another South Arabia, and 

 a third India and Ceylon. 



Synopsis of the g^enera : 



Claws simple ; scales on soles smootli ; tail at least as long as the body. 



Chamwleon Laurenti. 



Claws simple ; scales on soles spinose ; tail shorter than body Brookesia Gray. 



Claws bicuspid ; scales on soles spinose ; tail shorter than body . Rhamitholeon Giinther. 



Siebeurock ^ lias described the osteology of the Broolesia supercili- 

 aris Kuhl, which he shows possesses a number of peculiarities which 

 distinguish it from the species of the genus Chamwleon, and, in fact, 

 from all known genera of Vertebrata. From the fourth cervical verte- 

 bra to the eighteenth caudal, inclusive, the zygapophyses of each side 

 are connected by a longitudinal osseous bar. This bar gives origin on 

 the dorsal vertebrje to a transverse process which is above the true 

 transverse process and more prominent. It is called by Siebeurock 

 " accessorischer querer Fortsatz," which may be classicized into epidia- 

 pophysis. Further, the prezygapophyses are connected by a bony arch 

 which is fused on the middle line with the neural spine, on the dorsal 

 vertebrae, from the second to the ninth, inclusive. In the cranium the 

 frontal and parietal are greatly expanded. The former reaches the 

 orbit, excluding the pre- and postfrontals. The parietal excludes 

 the occipital from view when seen from above. There are teeth on the 

 prem axillary bone. 



In the genus Ghamcvleon the prefrontals and postfrontals exclude the 

 frontal from the orbit. The vertebra^ arc normal. 



In spite of the peculiarities of the Rhiptoglossa I supposed that they 

 were derived from the Pachyglossa. Many of their characters are pres- 

 ent in genera of the Agamidiii, leaving but few to be accounted for, as of 

 later and separate origin. Of the latter kind are the peculiarities of 

 the external nostrils, and metapodials. The characters of the premax- 

 illary, mandibular composition and scapular arch are nearly approached 

 or imitated by some of the Agamida*; and in some of the latter the 

 epipterygoid becomes much abbreviated. 



PACHYGLOSSA. 



Pachyglossa Wagler, Natiir. Syst. d. Amphib., 1830, p. 144. — Fitzinger, Syst. 



Kept., 1843, p. 43. — Gray, part, Cat. Liz. Brit. Mus., 1st ed., 1845, p. 5. 

 Strohilosaura Gray, Cat. Liz. Brit. Mus., Ist cd., 1845, p. 5. 

 Aci'odonta pachyfllossa + I'leurodonta iguania Cope, Proc. Acad. Nat. Sci. Phila., 



1864, pp. 225, 226. 



Petrous bone with superior plate not produced anterior to anterior 

 semicircular canal, and with a longitudinal wing only. Vertebrie procoe- 



' Sitzungsber. K. K. Akad. Wiss. Wien, CII, 1893, p. 71. 



