268 AXGtriD^, 



a. Dorsal scales obtusely keeled. 



Six or eight median dorsal series keeled . . 12. lingii, p. 274. 

 Three or four median series keeled 18. monticola, p. 278. 



b. Dorsal scales strongly keeled . . 13. liocephalus, p. 275. 



c. Dorsal scales smooth. 



Dorsal scales in 10 or 12 longitudinal 



series 14. modestus, p. 276. 



Dorsal scales in IG or 18 longitudinal 



series 15. rho7nbifer, p. 276. 



2. No azygos prefrontal. 



Dorsal scales in 14 longitudinal series . . 16. antauges, p. 277. 



3. An azvgos xirajfrontal, in contact with the frontal. 



Dorsal scales in 14 longitudinal series . . 17. ohscurus, p. 277. 

 Dorsal scales in 18 or 20 longitudinal 



series 19. moreletii, p. 278. 



1. Gerrhonotus oaxacae. 



Gerrhonotus (Abrouia) gramineus {no?i Cope), Bocourt, Miss. Sc. 



3Iex., Re2)t. p. 330, pi. xxvi. a. tig. 6. 

 oaxacae, Giinth. Biol. C.-Amer., Bept. p. 36, pi, xxiv. fig. A. 



Head very distinct from neck ; head-shields thick and rough in 

 the adult, convex on the temples ; a pair of small shields behind 

 the rostral ; five praefrontals, the central smallest and completely 

 enclosed between the others ; nasal separated from the rostral ; a 

 small supranasal ; two small superposed postnasals and two loreals, 

 second largest ; four small outer supraoculars ; frontal in contact 

 with the interparietal; ten upper labials, tenth largest and forming 

 with the lower temporals a regular obliquely ascending series of 

 four shields. Sides of neck covered with large irregular scales, 

 separated from the nuchal shields by a naked space with a few 

 scattered tubercular scales ; no fold on the side of the neck. Gular 

 scales larger than ventrals. Lateral fold very weak, without any 

 granular zone. Nuchal scales in four longitudinal series. Dorsal 

 scales in sixteen longitudinal series, the outer small and irregular, 

 much larger than the ventrals, obliquely quadrangular, the eight or 

 ten median series obtusely keeled (almost perfectly smooth in the 

 young) ; twenty-seven transverse series from the head to the base 

 of the tail. Ventrals in fourteen longitudinal series ; three ventral 

 transverse series correspond to two dorsals. The adpressed fore 

 limb reaches the eye ; the length of the hind limb equals two thirds 

 the distance from axilla to groin. Tail not twice as long as head 

 and body, round, subquadrangular at the base ; upper caudal 

 scales very obtusely keeled. Olive above, greenish-white inferiorly ; 

 young whitish with metallic gloss, with irregular transverse dark 

 olive bands on the bodv, limbs, and tail. 



