CROCODILIANS, LIZARDS, AND SNAKES. 231 



ity of the species, chiefly from Central America and Mexico, but a few 

 West Indian. 



The species inhabiting the United States belongs to the second sec- 

 tion of the genus. In size it is intermediate. 



The species of this genus are of arboreal habits, and they abound in 

 the tropical parts of America, and there only. They run with great 

 rapidity on the trunks and branches of trees, and dodge the pursuer 

 with great ease. Their food consists of insects, and to a large extent 

 of ants. 



* The ^1. vermiculatus of Cuba is said by Poey to dive into the water 

 after insects from bushes on the shore. The species of CJiamtvleolis 

 have a good deal the ai)pearance of chameleons, but the posterior cranial 

 arches are not so elevated. All the species have wonderful powers of 

 metachrosis, in which respect they quite equal the chameleons. Within 

 the genus Anolis, which embraces 120 species, there is a great range of 

 size and form. Thus the species A. cuvieri and ricordii of the Antilles 

 and edwardsii of Jamaica reach a foot and more in length, while the A. 

 distichus does not exceed 3 inches. The species cuvieri and ricor-dii, 

 with the smaller cristatellus of the Virgin Islands, are i)eculiar in the 

 possession of a caudal fin in the males, which is stretched on a frame 

 composed of the neural spines of the vertebne, as in the genus Basi- 

 lisciis. This structure disappears so insensibly in the allied species 

 that we can not sustain the genus Dactyloa Gray, proposed for such 

 forms. In coloration the species display much beauty and variety. 

 Thus, the A. edwardaii and cuvieri become a most vivid green under 

 appropriate circumstances. The A. heliactin of Mexico is a golden 

 yellow, and A. indcliellus of the Virgin Islands is also a metallic yellow. 

 The A. cyanopleurus of Cuba is a brilliant blue, as is also the Haytiau 

 A. ccdestinus. A. loysianus is of a kaolin white at times. The large A. 

 insignis of Costa Eica displays delicate dove and fawn colors, mingled 

 with more brilliant tints. The fans of the males are generally marked 

 with pink, purple, blue, or golden spots. 



Osteology. — The following osteological description is taken principally 

 from the A. caroliuensis, but other species which I have examined do 

 not differ from it. 



Premaxillary with long superior spine, and no inferior spine, but a 

 notch. Nasals distinct, separated by premaxillary spine. Frontal and 

 parietal bones each undivided, the pineal foramen on the coronal suture. 

 Prefrontal large, not extending over orbit; lachrymal narrow, in con- 

 tact Avithjugal. Postfroutal small, distinct; i^ostorbital large. Supra- 

 temporal slender, forming the greater part of the supratemporal arch, 

 its anterior extremity in contact with the postorbital and ])ostorbital 

 process of jugal bones. Paroccipital small; parietoquadrate arch well 

 developed. Supraoccipital loosely attached, coossitied Avith exoccipital. 



The frontal bone is grooved on the median line below. The post- 

 optics are within the epipterygoids, and are curved, inclosing a subcir- 



