CROCODILIAN^, LIZARDS, AND SNAKES. 561 



Dorsal scales forniing transverse .s<rics only. 



Lateral scales like <l0rsnls -Irthrosaum Bonlen-er. 



Lateral scales small, irregnJar. "^ 



^ Prionodactijlus O'Shaughne.v y 



Dorsal scales forming regular transverse and longitudinal 



/?T^ 1 , ^*^"^^ Cercosaum Wagler. 



(5 Dorsal scales smooth or feebly keeled. 



* Dorsal scales not larger than ventrals. 



Scales not forming uninterrupted series round the body; a 

 continuous series of femoral and pneanal pores. 



Placosovia Tschudi. 

 Scales subequal, forming uninterrupted series round the 



^ , ^"^^y ^nadmGray. 



Scales not forming uuinterrupted annuli, the laterals being 



much smaller; dorsals hexagonal; collar-fold feeble: 



males without femoral pores. 



Ecpleopus Dumdril and Bibron. 

 Scales not forming uninterrupted annuli, the laterals being 



much smaller; collar-fold strong; males %Yith femoral 



* # T^ P^^^^f Euspondylus Tschmli. 



Dorsal scales larger than ventrals. 



Scales quadrangular, smooth; collar-fold strong; both sexes 



AA. No prefrontals. ^i*^ ^'^-o-'^l Pores ^.,a/.« Gray. 



Dorsal scales hexagonal, striated, imbricate; collar-fold feeble. 



r.^„„ 1 1 , , , . PhoUdohoUts Peters. 



Dorsal scales keeled, juxtaposed, separated from ventrals by a wide zone of 



T. , , ^^^''^^^ s^'^les ; collar- fold strong .... Oreosaurus Peters 



Dorsal scales smooth or striated, juxtaposed, separated from ventrals by a 



TTT V«...-i • ■■ , . ^f'^ ' collar- fold strong Proctoporus Tschudi. 



III. Nostril pierced between the nasal and the first labial; no ear opening (except 



Stenolepis). 

 A. Digits rudimentary or absent. 



* Fronto-nasal and prefrontal plates present. 



Digits clawed distinct. 4-4 v„^j„„^„^ t, , 



if»-t^ . , --i^, * * Aco/ecosawrMs Boulenger. 



I' ronto-nasal present; no prefrontals. 



a Claws jiresent. 



Digits 4-2 ., 



n- ■. , . iieaqnipes Coxie). 



Digits 4-1 (•,.,, ^ 



■p.. ., „„ ^ni8oclo)itiim Co-pe. 



mJiuli ■• ^ierodactylns Gray. 



aa Claws absent. ° 



Digits 3-1 rr t.- T^.x . 



*** IT. X , „ ( opAjas Fitzinjrer. 



I ronto-nasals, prefrontals, and claws wanting 



Digits3-1 ^ ,. 



T^ ,. , ,. ., ■ Ophtognomon Cove. 



Fore hmbs undivided ; hind limbs absent. . . P,.n„„„ n^L 



AA. Digits well developed; inner finger rudimentary'." "(Lo'wer eyelid with 

 transparent disc.) 

 Dorsal scales narrow; hexagonal-lanceolate, keeled; no meatus auditorius. 



e„„i ■ -1 JJelerodacti/lua Snix. 



Scales similar; a meatus auditorius and fronto-parietal plates; inner finder 



TV xr...i w •, , developed Sfeuolepis Bonlei.^ev 



n. Nasal plates widely separated by a fronto-nasal; ear exposed; inner finder [f 



, ^ ,., , , distinct, clawless. " ' 



A. Eyelids developed. 



Dorsal scales narrow, hexagonal-lanceolate, keeled. . Perodactulus Reinhardt 



NAT MUS 98 36 andLiitken. 



