LACERTILIA LACERTAE 



CHAP. 



Fam. 7. Lanthanotidae. Pleurodont. Tongue short and bifid. Post- 



fronto-squamosal arch absent. No osteoderms. 

 Borneo, p. 541. 



Fam. 8. Varanidae. Pleurodont. Tongue very long, bifid, smooth, 



very protractile. No osteoderms. Postorbital 

 and temporal arches incomplete. Old World, 

 p. 542. 



Fam. 9. Xantusiidae. Pleurodont. Tongue very short and scaly. No 



osteoderms. Supratemporal fossa roofed over 

 by the cranial bones. No movable eyelids. 

 Central America and Cuba, p. 547. 



Fam. 10. Tejidae. Teeth solid, almost acrodont. Tongue long, 



deeply bifid, with papillae. No osteoderms. 

 Limbs sometimes reduced. America, p. 547. 



Fam. 11. Lacertidae. Pleurodont. Tongue long, bifid, with papillae 



or folds. With osteoderms on the head. 

 Supratemporal fossae roofed over by the cranial 

 bones. Old World, p. 549. 



Fam. 12. Gerrhosauridae. Pleurodont. Tongue long, witli papillae, but 



feebly nicked. With osteoderms on the head 

 and body, roofing over the Supratemporal 

 fossae. African sub-region, p. 559. 



Fam. 13. Scincidae. Pleurodont. Tongue scaly, feebly nicked. 



Osteoderms on the head and body. Limbs 

 often reduced. Cosmopolitan, p. 559. 



The following five " families " are much degraded in con- 

 formity with their usually subterranean life, see p. 496: 

 Fam. 14. Anelytropidae. Without limbs. Body covered with scales. 



Mexico and Africa, p. 564. 



Fam. 15. Dibamidae. Vermiform, limbless body covered with scales, 



without osteoderms. Australasia and Nicobar 

 Islands, p. 564. 



Fam. 16. Aniellidae. Without limbs ; body covered with scales, with- 



out osteoderms. California, p. 564. 



Fam. 17. Amphisbaenidae. The body is covered with soft skin, forming 



numerous rings with mere vestiges of scales. 

 Without limbs, except Chirotes with four- 

 clawed fore-limbs, p. 565. 



Fam. 18. Pygopodidae. Snake-shaped, with scales. Fore-limbs absent, 



hind-limbs appearing as a pair of scaly flaps. 

 Australia, p. 567. 



These eighteen " families " of the Lacertae fall into four main 

 groups. We naturally assume that the presence of osteoderms and 

 of complete cranial arches indicate more archaic conditions than 

 their absence, just as we conclude that limbless forms have been 

 evolved from creatures with fully developed limbs. We arrange 

 the four groups with their families as follows : 



