18 IGUANIDE, 
VI. Tail strongly compressed; dorsal scales much larger than the 
laterals. 
Dorsal and ventral scales rhomboidal, imbri- 
Cale; REEL a: aiacsaratsl sup noek 4.00 ooh ees 63. pulchellus, p. 67. 
VII. Tail cylindrical or feebly compressed; dorsal scales larger 
than the laterals whenever the digital expansions are distinctly 
developed ; dorsal and lateral scales equal or nearly equal in a 
few species in which the third phalanx of the fourth toe is not 
distinctly wider than the basal. 
A. Dorsal scales as large as or larger than the ventrals, 
1. Head (to occiput) longer than the tibia. 
a. Dorsal scales not larger than the ventrals. 
Dorsal and ventral scales large; occipital en- [p. 68. 
Tae ed ic sent cs cheers tha Were cence leach ethane 64. semilineatus, 
Scales smooth ; occipital not larger than the 
surrounding scales................ 0005 91. oxylophus, p. 84. 
b. Dorsal scales larger than the ventrals. 
u. Scales on upper surface of snout smooth. 
Dorsal and ventral scales keeled .......... 65. spectrum, p. 69. 
Dorsal and ventral scales smooth .......... 67. lionotus, p. 70. 
f. Scales on upper surface of snout keeled or striated. 
Dorsal scales feebly keeled or striated ...... 66. cyanopleurus, 
Dorsal scales strongly keeled, in about ten [p. 69. 
longitudinal series ................000. 86. humilis, p. 82. 
Dorsal scales strongly keeled, in seven series. 87. quayyulus, p. 83. 
2. Head not, or scarcely, longer than the tibia; dorsal and 
ventral scales sharply keeled. 
Dorsal scales larger than ventrals; tibia as long [p. 83. 
as the head iy eves ve gavin recs ene sae ka 88. tropidonotus, 
Dorsal scales larger than ventrals; tibia 
shorter than the head ..............., 89. uniformis, p. 84. 
Dorsal scales not larger than ventrals ...... 90. metallicus, p. 84. 
B. Dorsal scales smaller than ventrals ‘. 
1. The length of the tibia is less than the distance between ~ 
the end of the snout and the ear, 
a. Ventral scales smooth. 
Head elongate ................,. ee 68. alutaceus, p. 71. 
6. Ventral scales keeled. 
a. Occipital considerably longer than the greatest dia- 
meter of the ear-opening. 
* In a few species very slightly. 
