98 



GENERAL EVOLUTION. 



Abdominal ribs. 



Iguanidje. 

 Polvchrus. 



AGAMIDiE. 



No abdominal ribs. 



llibs greatly prolonged into a lateral wing. 



* * Draco. 



Ribs not prolonged. 



Arboreal types, generally compressed. 



A dorsal and caudal fin supported by bony rays. 



Basiliscus (no lem. pores). Lophura (pores). 



No vertebral fin. 



No femora] pores. 

 Form slender, scales in Calotes. 



equal series. Bronchocc 



Form elongate ; eyebrows 



Gonyocephalus. 



cela. ) 



Lasmanctus. 



elevated, tail compressed. 

 Form stouter, scales less 



regular. 



Hypsibates. 



Femoral pores. 



Brachylophus. 



Ophryoessa. 

 Tiaris. 



Diporophora. 



Pliysignathus. 

 * * 



Low crested; small hyoid 



disk. 

 High crested; large hyoid 



disk. Iguana. 



Tail with spinous whorls. Cyelura. 



Terrestrial types of flattened form. 



Femoral pores. 

 Tail with whorls of spiny 



scales. Hoplocercus. Uromastix. 



Tail long, simple; scales 



small. Crotaphytus. Liolepis. 



Tail simple, scales large. Sceloporus. * * 



No femoral pores ; preanal pores. 



Tail with whorls of spines. * * Stellio. 



Tail simple, not elongate, 



ear open. Proctotretus. Agama. 



Neither femoral nor anal pores. 



Much flattened, tail short, scales irregular. 



Ear exposed. Phrynosoma. Moloch. 



Ear concealed. (Doliosaurus, s. g.) j Segd'Sus!'"'' 



A similar parallel may be drawn between the American Teidas, 

 and the Old World Lacertidae, and in fact between all the families 

 of the Lacertilia Leptoglossa. I have added to these for compari- 

 son two families of the Typhlophthalmi. Each family embraces 

 one or more series, and these exhibit a remarkable similarity in 

 the relative development of the limbs and digits ; among the 

 higher groups the parallelisms lie in the arrangement — as greater 

 or less separation — of the head shields. The Scincidae are cosmopo- 

 lite ; the Gymnophthalmidae, which have the eyelids of their foe- 

 tus, are Australian ; the Sepsidas, either larval or senile in head 

 shields, are mostly Ethiopian. 



