27. TROPIDURUS. 173 
male; lower surfaces yellowish or greenish white, throat and chest 
frequently spotted with black; the male’s throat usually black. 
millim. millim 
Total length ...... 250 Fore limb ........ 44 
ead: cists ears te oe 20 Hind limb........ 2 
Width of head .... 16 OP aah..| scaiyihsa ince Gata 160 
BOO ye istered na des 70 
Galapagos Islands. 
a,b,c-9. §,9,&yg. Chatham and Charles C. Darwin, Esq. [P.]. 
Islands. (Types.) 
ho. Albemarle Island. Commander Cookson [P.]. 
a. Her. o.. Abingdon Island. Commander Cookson [P.]. 
2. Tropidurus pacificus. 
Tropidurus (Craniopeltis) pacificus, Steindachn. Festschr. zool.-bot. 
Ges, Wien, 1876, p. 318, pl. ii. figs. 2, 3. 
Distinguished from 7’. grayi by the much smaller and less strongly 
keeled dorsal scales; they little exceed the ventrals in size and are 
never mucronate ; ninety-one to ninety-five scales round the middle 
of the body. Dark olive above, with small black and greenish spots ; 
antehumeral fold black; lower surfaces greenish or bluish-grey, 
throat and chest spotted with black. 
Size and proportions as in the preceding. 
Galapagos Islands. 
a,b. So. Abingdon Island. Commander Cookson [P.]. 
3. Tropidurus occipitalis. 
Lemopristus occipitalis, Peters, Mon. Berl. Ac. 1871, p. 645. 
Scales on the snout keeled; seven or eight broad supraoculars ; 
occipital very large, twice as broad aslong. A strong transverse 
gular fold, with denticulated edge, in front of the antehumeral fold. 
A dorsal crest of very pointed scales, extending onthe tail. Dorsal 
scales keeled, larger than the smooth ventrals; lateral scales 
smallest, keeled. Grey-brown above, with four irregular rhom- 
boidal transverse spots, the first on the middle of the nape, the 
second between the shoulders, the two others on the anterior part 
of the back; on each side of the back a yellowish-green metallic 
longitudinal band ; antehumeral fold black ; lower surfaces yellowish. 
Peru. 
4, Tropidurus bocourtii. 
Aneuporus occipitalis, Bocourt, Miss. Se. Mex., Rept. p. 215, pl. xviii. 
fig. 1 
Chaniopoitie occipitalis, Cope, Journ. Ac. Philad, (2) viii. 1876, 
p. 173. 
Upper head-scales smooth; a series of four or five transverse 
