120 Mr. G. A. Boulenger on the 



with irregular, arborescent, or radiating channels ; anterior portion 



of tongue retractile. 

 Fam. 10. Aniellid^. No interorbital septum, no columella cranii, no 



arches. 

 Fam. 11. HKLODERMATiDiE. Postorbital arch present, postfronto-squa- 



mosal arch absent ; pre- and postfrontals in contact, separating 



the frontal from the orbit. 

 Fam. 12. Varanid^^. Postorbital arch incomplete ; postfronto-squa- 



mosal arch present ; supratemporal fossa not roofed over ; nasal 



bone single ; tongue deeply bihd, sheathed posteriorly. 



C. Tongue covered ipifh imhricate scale-like papillcc or with oblique plica ; 

 clavicle dilated lyroximalhj ^ frequently loop-sliapcd. 



Fam. 13. Xantusiid^. Parietals distinct; postorbital and postfronto- 

 squamosal arches present ; supratemporal fossa roofed over. 



Fam. 14, TEiiDiE. Postorbital and postfronto-squamosal arches present; 

 supratemporal fossa not roofed over ; no osteodermal plates. 



Fam, 15. Amphisb^enidje. No interorbital septum ; no columella 

 cranii ; no arches ; premaxillary single. 



Fam. 16. LACERXiDiE. Arches present ; supratemporal fossa roofed over ; 

 premaxillary single ; no osteoderuuil plates on the body. 



Fam. 17. GEPEHOSArRiDiE. Arches present ; supratemporal fossa roofed 

 over; premaxillary single; body with osteodermal plates with 

 regular channels (a transverse one anastomosing with perpendicular 

 ones). 



Fam. 18. SciNCiDiE. Arches present ; premaxillary double ; body with 

 osteodermal plates as in the preceding. 



Fam. 19. Anelytropid^. Premaxillary single; no arches; no osteo- 

 dermal plates. 



Fam. 20. Dibamid^e. Premaxillary double ; no interorbital septuui ; no 

 columella cranii ; no arches ; no osteodermal plates. 



Suborder II. RIIIPTOGLOSSA. 

 Fam. 21. Cham.^leontid.?5. 



The Geckonidce and ILublepharidce^ whicli dilFer from all 

 other families in combining a dilated clavicle with a simply 

 papillose tongue, are well distinguished from each other by 

 the vertebree, which are amphicoelous in the former and pro- 

 coelous in the latter. As characters of minor importance may- 

 be mentioned the coossification of the parietal bones in the 

 Eublepharid^, while they remain distinct in the Geckonida?, 

 which are also distinguished, constantly I believe, by having 

 one bone less in the mandible, the supra-angulare having 

 coalesced with the angulare. 



Next come the Uroplatidce^ which are now for the first time 

 separated from the Geckos. Although agreeing in most 

 respects with the latter, their sternal apparatus differentiates 

 them widely ; the clavicle is slender, not at all dilated, and 

 the interclavicle is reduced to a minute bone. Except the 

 chameleons, all other lizards in which the pectoral arch is not 



