ART. 12 REVISIOlsr OF LIZARDS OF GENUS CTENOSAURA BAILEY 41 



spine near center; scales on upper side of hind feet toward toes enlarged, keeled, 

 and spinous; 7 large femoral pores on each side; tail somewhat constricted at 

 insertion, much depressed at base, becoming subcylindrical posteriorly; caudal 

 scales above and laterally in whorls of large spinous scales, separated by a single 

 row of smaller fiat scales, the central one being spinous, however; in the spinous 

 row the median scales are the shortest, the lateral one the longest, while in the 

 smaller and smooth row the proportion is reversed, so that the anterior outline 

 of the large row is concave and the posterior outline of the small row is convex; 

 the outlines of each pair or rows perfectly straight; in the spinous row the scale 

 on each side of the central one is without a spine; the lateral spines are straight; 

 the central falcate, the median spines form a caudal crest, in the basal half of 

 which the spines alternate large and small, according to whether they belong to 

 the large or small row; caudal scales below much smaller, three rows corresponding 

 to each pair above, strongly keeled and pointed posteriorly. 



Adult female: Same as male except that the dewlap is smaller and 

 the dorsal crest is made up of shorter spines. 



Measurements. — u.s.n.m. no. 22703, 



adult, male 



Length of head 40 mm. 



Length of body 140 mm. 



Length of tail 230 mm. 



Total length 410 mm. 



Width of head over orbits 23 mm. 



Coloration. — Green with yellow variegations on throat, dewlap, and 



lateral folds; dorsal crest pale yellowish ; on body several ill-defined, 



'chevron-shaped blackish bands, which do not cross the dorsal crest, 



but the posterior three of which reach the abdomen; tail marked with 



broad bands of dull blackish brown. 



RemarJcs. — Doctor Stejneger says: 



Another specimen (No. 22704, U.S.N.M.) of the same age and sex, which dif- 

 fers in no essential feature from the one described, except that the dorsal crest 

 contains 36 spines only, and that the interruption between the doral and caudal 

 crests is complete, being not even indicated by a row of carinated scales. Another 

 peculiarity is that one of the small scales at the base in front of each dorsal spine 

 has developed into a very minute spine. A third specimen (No. 24459, U.S.N.M.) 

 is very young, only 198 mm. (7.8 inches) long. The dewlap is already well 

 indicated, being 5 mm. (0.2 inch) deep; all the other diagnostic characteristics 

 are also present and well marked. The dorsal crest is quite pronounced, the 

 spine being triangular, about as high as long; the large ones standing some 

 distance apart, the interval being wider than the basis of the spines; the small 

 ones as the anterior and posterior ends are placed quite close; the number of 

 the spines is 37; the crest perfectly interrupted on the rump. Eight femoral 

 pores. Color essentially as in adults. 



The material from which the type was described was received at 

 the United States I^ational Museum in 1899 from Mrs. K. I. P. 

 McElroy of Gualan, Guatemala. 



In May, 1926, Doctor MacPhail, of the United Fruit Co. Hospital 

 at Quirigua, forwarded to Dr. Thomas Barbour, at the Museum of 

 Comparative Zoology, 12 very fine specimens. They also were taken 



