REPTILIA 563 



A row of enlarged gular scales parallel the gular fold and a small, 

 single spine may be found on each side at the posterior gular border. 

 Two longitudinal folds are present on each side of the cervical region. 

 These folds descend forward and obliquely downward to the plane 

 of the gular fold. 



The trunk is depressed and is broadly fusiform in shape. It is 

 flattened ventrally and tapers posteriorly toward the pelvis. 



The anterior Unibs spring one from each side of the body near the 

 anterior end of the trunk. They are divided into three divisions : 

 proximal or hrachium, middle or antehrachium, and distal or manus. 

 The distal division is terminated by five clawed digits. The first 

 digit is the shortest. It is designated as the thumb or pollex. 



The posterior limbs arise one from each side of the body near the 

 posterior end of the trunk. They are also divided into three regions : 

 proximal or thigh, middle or shank, and distal or foot. The foot, 

 like the hand, ends with five clawed digits. The first digit, or hallux, 

 is the shortest. The ventral surface of the thigh bears twelve to 

 fifteen femoral pores, whose function is obscure. They are present 

 in adult males only. 



Between the thighs on the ventral aspect of the body is a slitlike, 

 transverse vent, or anus. It is the common outlet for the digestive 

 and urinogenital systems. The short tail is broad at the base but 

 tapers quickly toward the distal end. In males two genital swellings 

 lie one on each side of the ventral surface of the broadened proximal 

 region of the tail just posterior to the vent. 



Like most reptiles, these lizards shed their thin epidermal cover- 

 ing periodically. The variable color pattern is brighter for a time 

 after this skin is cast. 



Digestive System 



The alimentary canal is composed of the following organs in order : 

 mouth, esophagus, stomach, small intestine, large intestine, rectum, 

 cloaca, anus. Several accessory organs and structures are teeth, 

 tongue, pancreas, and liver. 



The upper and lower jaws form the anterior boundary of the aper- 

 ture of the mouth, and are each provided with a single row of small, 

 faintly tricuspid teeth. These teeth are not adapted for mastication 

 but for seizing and holding prey. The posterior nares are apertures 

 situated a little behind the end of the snout and separated from one 



