Garman.] 406 [June 21, 



specimens the occiput is rounded; a few scales on each side enlarge 

 and thicken so as to form angles as the animal approaches maturity. 

 Adults have more of yellow or gamboge; frequently they are freckled 

 with scales of yellow. The scales of the crest are very small in the 

 young. This species retains its integrity from Acapulco to Rio 

 Janeiro; the variations to be noted in the whole range are slight 

 compared with those of individuals from a single locality. A collec- 

 tion of twenty specimens from S.intarem includes some mottled 

 with yellow, as are very large ones from Panama and Turbo, others 

 of the colors of Spix's figure of squamosa, others of those of his 

 viridis, others having the greyish blue of ccerulea, and yet others 

 fairly represented by his figures of emarginata and lophyroides. 



Individuals vary in respect to the number of tubercles on the neck, 

 the amount of convexity and number of prefrontal scales, and the 

 number and arrangement of the row of large scales on the side of 

 the head below the ear. 



Basiliscus mitratus Daud. 



Specimens from various places between Mexico and the east side 

 of the Gulf of Daricn. Males from the northern localities have the 

 brown markings and the longitudinal lines more distinct; the females 

 are more indistinctly marked, and usually more of a dingy rusty 

 brown. Southern specimens are less bright, and the transverse bands 

 are hardly to be observed. In the same locality there is much differ- 

 ence noticeable in specimens of various ages in respect to shape and 

 size of helmet and the scales covering it, also in regard to the height, 

 number of rays, and the scaling in the crests. The rays of the dor- 

 gal and caudal crests increase in length and number with age; a 

 young adult male possesses from one to several less in number than 

 an old one. The helmets and the scales on their sides increase in 

 size with age; with little or no increase in number the scales expand 

 as the crest enlarges, so that the old male has more large scales on 

 the helmet than the young. Females do not develop the helmet. 

 When broken the tail is reproduced. The animal which served as 

 the type of Corytlieolus vittatus Kaup. was no doubt a young male of 

 this species, taken at the time the helmet began to enlarge, before 

 much change had occurred in the crests. Corytliophanes cristatus 

 (Merr.) Boie differs from the species of Basiliscus in the skull, 

 in a crest along the back of the entire neck, a small circular nasal 

 plate which does not rest upon the first labial, and a flat head cov- 

 ered with flat scales, which are similar over the entire surface. C. oris- 





