334 TEIIDE. 
Dorsal scales smooth or striated, juxtaposed, separated from ventrals 
by a fold; collar-fold strong.... 26. Proctoporus, p. 412. 
III. Nostril pierced between the nasa] and the first labial; no ear- 
opening. 
A. Digits rudimentary or absent. 
Digits distinct, clawed ; a pair of preefrontals and a frontonasal. 
27. Scolecosaurus, p. 416. 
Digits, if distinct, clawless; a frontonasal; no preefrontals. 
28. Cophias, p. 417. 
No frontonasal, no prefrontals.... 29. Ophiognomon, p. 420. 
B. Digits well developed; inner finger rudimentary. 
Dorsal scales narrow, hexagonal-lanceolate, keeled. 
30. Heterodactylus, p. 422. 
IV. Nasal plates widely separated by a frontonasal; ear exposed ; 
inner finger, if distinct, clawless. 
A. Eyelids developed. 
Dorsal scales narrow, hexagonal-lanceolate, keeled. 
31. Perodactylus, p. 423. 
All the scales rounded, imbricate, two median dorsal and two ven- 
tral series strongly enlarged transversely. 
32. Iphisa, p. 424. 
All the scales rounded, imbricate, subequal. 
33. Tretioscincus, p. 425, 
B. No eyelids; scales cycloid, quincuncial. 
No prefrontals ; frontoparietals present. 
34. Micrablepharus, p. 426. 
Preefrontals present; no frontoparietals. 
35. Gymunophthalmus, p. 427. 
1. TUPINAMBIS. 
Tupinambis, part., Daud. Rept. iii. p. 6. 
Sauvegardes, part., Cur. R. A. ii. p. 26. 
Teius, part., Merr. Tent. Syst. Amph. p. 60. 
Monitor, Fitzing. N. Classif. Rept. p. 21. 
Exypnestes, Kaup, Isis, 1826, p. 87. 
Podinema, Wagl. Syst. Amph. p. 153; Wiegm. Herp. Mex. p. 8. 
Ctenodon, Wagl. l.c.; Wiegm. l. c. 
