19. AGAMA. 337 



2. Fifth toe extending as far as first ; ear-opening larger than 

 the eye-opening. 



Third toe slightly longer than fourth; 



ventral scales smooth 18. aculeata, p. 351. 



Third toe slightly longer than fourth ; 



ventrals keeled 19. armata, p. 352. 



Fourth toe slightly longer than third ; 



ventrals smooth 20. atra, p. 352. 



B. Dorsal scales equal. 



1. A slight denticulation or crest on the vertebral line. 



Dorsal scales considerably larger than ven- 

 trals 21. mossambiea, p. 353. 



Dorsal scales scarcely larger than ventrals . 22. kirkii, p. 354, 



2. No dorsal denticulation or crest. 



a. Body moderately depressed ; dorsal scales mucronate. 



a. The longest spines near the ear and on the sides of the 

 neck at least two thirds as long as the diameter of 

 the ear-opening. 

 Dorsal scales much smaller than the caudals, 

 40 to 50 from the origin of the fore limbs 



to the origin of the hind limbs , 23, spinosa, p. 355. 



Dorsal scales nearly as large as the caudals, 

 26 or 27 from the origin of the fore limbs 

 to the origin of the hind limbs 24, rueppellii, p. 355. 



/3. The longest spines near the ear and on the sides of the 

 neck not two thirds the diameter of the ear-opening. 



Four .or five labials anterior to the front 



border of the eye ; fourth toe as long as 



the distance from the posterior border of 



the eye to the end of the snout 25, colonorum, p. 356. 



Seven or eight labials anterior to the front 



border of the eye ; fourth toe as long as 



the distance from the posterior border of 



the eye to the nostril 26, hibronii, p, 357, 



6. Body much depressed ; dorsal 

 scales not or but very slightly 

 mucronate 27. planiceps, p. 358. 



III. Occipital scale not enlarged; caudal scales forming more or 

 less distinct annuli ; ventral scales smooth ; digits compressed. 



A. The caudal segments, if at all distinct, composed of more than 

 two whorls of scales. 



1. Scales on the vertebral region unequal, irregular. 

 Nostril pierced on the canthus rostralis . . 28. atricoUis, p. 358. 

 Nostril pierced below the canthus rostralis 29, cyanogaster, p, 359. 



