172 IGUANIDZ. 
Dorsal scales nearly as large as ventrals ; 
sides of neck with groups of erect 
spinose scales ..... 6... cece eee ees 6. spinulosus, p. 175. 
B. No dorso-nuchal crest. 
1. Dorsal scales keeled. 
Dorsal scales scarcely larger than ven- 
trals; enlarged supraocular scales not 
occupying more than half the width of 
the supraocular region ..........+. 7. torquatus, p. 176. 
Dorsal scales scarcely larger than ven- 
trals; supraocular region nearly en- 
tirely covered by a series of transverse 
band-like scales ............00005- 8. hygomi, p. 177. 
Dorsal scales at least twice as large as 
PVOUOE GIS: son avene Qs meaner he ad Sacoenedm 9. hispidus, p. 177. 
2. Dorsal scales smooth.......... 10. semitentatus, p. 178. 
Il. Nostril lateral; ventral scales trica- 
TIM ALE! va) 64-2 bat ached a eegereesre- ess 11. blainvillii, p. 178. 
1. Tropidurus grayi. 
Leiocephalus grayii, Gray, Cat. p. 218. 
Leiocephalus grayil, Bell, Zool. Beagle, Rept. p. 24, pl. xiii. fig. 1. 
Holotropis grayii, 4d. Dum. Cat. Méth. Rept. p. 70, and Arch. Mus. 
viii. p. 538. 
Craniopeltis grayii, Peters, Mon. Berl. Ac. 1871, p. 645. 
bivittata, Peters, l. ¢. 
Tropidurus (Craniopeltis) grayii, Stetndachn, Festschr. zool.-bot. Ges. 
Wien, 1876, p. 310, pl. ii. fig. 1. 
Upper head-scales smooth; a series of five to seven transverse 
band-like supraoculars, covering the greater part of the supraocular 
region ; occipital as broad as or broader than the latter, usually 
broader than long; ear-opening with a more or less developed fringe 
of pointed scales anteriorly. A strong curved antehumeral fold ; 
sides of neck more or less strongly plicate, the folds forming a pouch 
between the ear and the antehumeral fold. A dorso-nuchal crest, 
well developed in the male, reduced to a mere serrated ridge in the 
female. Dorsal scales large, much larger than ventrals, very 
strongly keeled, ending in a mucro or spine ; the keels forming con- 
tinuous slightly oblique longitudinal series; lateral scales smaller, also 
strongly keeled; ventrals smooth; fifty-five to sixty-five scales round 
the middle of the body. The adpressed hind limb reaches the ear, or 
between the latter and the eye. Tail once and a half to once and 
two thirds as long as head and body, compressed, especially in the 
male, crested or serrated like the back. Olive above, spotted with 
black ; sometimes a light yellowish band on each side of the back 
and another from axilla to groin; antehumeral fold black in the 
