154 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
CYCLURA RILEYI Stejneger. 
Plate 7; Plate 15, fig. 3, 4. 
Stejneger, Proc. Biol. soc. Wash., 1903, 16, p. 129. 
Diagnosis:— Nasals broadly in contact with the rostral. Scales 
of the top of head flat or only slightly swollen. Prefrontal region 
covered by a pair of elongate supranasals in contact with the nasals 
and also in contact with each other, each supranasal followed by two 
large prefrontals, the posterior the larger, the prefrontals of each 
side in contact with each other but separated from the series of the 
opposite side by two rows of large scales. Top of head behind pre- 
frontals covered with numerous small scales; the scales of the supra- 
ocular region much smaller than the others; except for a grouping 
of a few large scales on each side of the occipital, and a semirosette 
of enlarged scales in the frontoparietal region, these scales without 
a definite arrangement. Canthus rostralis consisting of a group of 
three scales, the canthal and precanthal about the same size and larger 
than the third scale. Dorsal crest interrupted on both shoulders 
and rump, formed of scales of varying height; nuchal section formed 
of about twenty spines about the same in width and varying from 
one to ten millimeters in height, according to the proximity to the 
extremities of the series, back section formed of seventy-six spines, 
scarcely over a millimeter in height, except for the last fourteen spines 
which average about 5 millimeters; caudal section formed of heavier 
spines than those of the back, about 4 millimeters in height. Limit- 
ing row of each verticle clearly differentiated. Ground color, bluish 
gray, heavily blotched with confluent tawny yellow spots except on 
the posterior ventral surface, which is uniform yellowish gray; head 
very much paler, tail darker than the rest of the body. 
Habitat:— Two small cays in the large salt water lagoon on Watlings 
Island. 
Description:— Adult male, M. C. Z. 10918, Watlings Island, Baha- 
mas, April, 1915, W. W. Worthington. 
Rostral as wide as the mental broadly in contact with the nasals; 
nasals very large, about the size of the posterior prefrontals, broadly 
hexagonal, in broad contact with each other; each nasal perforated 
posteriorly by an elongate nostril; each nasal in contact with an 
elongate supranasal and two postnasals; nasals and supranasals 
