Vol. II, Pt. I] VAN DENBURGH—SLEVIN—GALAPAGOAN LIZARDS 151 



1877, Liocephalus paciiicus, GiJNTHER, Proc. Zool. Soc. Lond., 1877, p. 

 67 (part). 



1890, Tropidurus pacificus, Baur, Biol. Centralbl., X, 1890, p. 479; 

 BouLENGER, Ann. and Mag. Nat. Hist., (6), VII, 1891, p. 501 (part). 



1892, Tropidurus habelii, Baur, Festschrift fur Leuckart, 1892, p. 271 ; 

 Heller, Proc. Wasliington Acad. Sci., V. 1903, p. 81. 



Diagnosis. — Neck folds fewer, sides of neck covered with 

 scales instead of granules; more than 65 scales around mid- 

 dle of body ; no light longitudinal dorsolateral stripes ; no red 

 in coloration ; dorsal crest in males higher than in any other 

 race. 



Types. — Vienna Museum. Collected by Dr. Habel on "In- 

 defatigable [ ?] and Bindloe Islands," Galapagos Archipelago. 



Distribution. — This species is peculiar to Bindloe Island, 

 Galapagos Archipelago. 



Material. — The Academy's collection contains about one 

 hundred and seventy-three specimens, of which forty males 

 and seventy-five females have been included in the table of 

 scale counts. 



Description of adult male No. 12397. — The head is covered above with 

 smooth scales; interparietal largest, broader than long; five or six large 

 supraoculars ; superciharies imbricate ; five superior and five inferior 

 labials, to below middle of eye ; rostral very broad and low ; symphyseal 

 broad, followed by a series of large sublabials, of which all but the first 

 are separated from the infralabials by a row of smaller plates. Ear- 

 opening large, with an anterior denticulation of five or six long, narrow 

 scales. Side of neck between ear-opening and fore limb with compara- 

 tively few folds, covered with keeled, imbricate scales. A strong ante- 

 humeral, but no complete gular, fold. A well-developed median dorsal 

 crest begins about half the length of the interparietal behind this plate, 

 and runs continuously to and along the tail, being highest on the proximal 

 fourth of the tail. The dorsal regions of the neck, body, and tail are 

 covered with rather small, keeled, mucronate scales, which, on the body, 

 change gradually to smaller, keeled, mucronate laterals. These . again 

 change gradually into the smooth ventrals, which are a little smaller than 

 the dorsals. The gular scales are smooth, smaller posteriorly, smallest 

 below the ears. The scales on the chest are largest, smooth and imbri- 

 cate. The limbs are provided above v/ith keeled, and below with smooth, 

 scales. The posterior surface of the thigh is covered with rather small 

 scales. The lateral caudals are strongly keeled and mucronate, while the 

 inferior caudals are smooth proximally, but become keeled on the distal 

 portion of the tail. 



The general coloration in alcohol is grayish brown, with little evidence 

 of darker markings except a black blotch in front of the shoulder. The 

 posterior gular region is darker. The head, neck, body, limbs, and tail 

 are very slightly specked with Hght bluish gray, but there is no band of 

 the same color along the medium dorsal region. The hind limbs are not 

 distinctly spotted with black. The lower surfaces are yellowish white 

 more or less suffused with brown. 



