REPTILIA 555 



Our species are found in open, sunny, sandy places. If disturbed 

 they skim over the ground with great rapidity, but if hard pressed 

 they take refuge in burrows. Insects make up the bulk of their 

 food. All the species lay thin-shelled eggs which are deposited in 

 shallow excavations in the sand to be hatched by the heat of the 

 sun. 



Family Scincidae (skinks, or smooth lizards). — This is one of the 

 largest families of lizards, being composed of over four hundred 

 species arranged in thirty genera. Three genera containing sixteen 

 species are fonnd in the United States. They are more abundant 

 both in number of kinds and in number of individuals in tropical 

 regions, especially in tropical parts of the old world and in the 

 Australian regions. South America has fewer skinks than any other 

 region in the world. 



All the skinks are relatively small lizards, the largest in this coun- 

 try seldom attaining a length of ten inches. The scales are smooth 

 and usually shining. The color varies with age. The young are 

 darker than the adults and color patterns of lines present on the 

 young often disappear on adults. There is great variation in the 

 development of the limbs. Most of our forms have one or both 

 pairs of legs. 



The skinks are diurnal, feeding by day and seeking a hiding place 

 at night. Many old world kinds are burrowers in sand, but of all 

 American forms only one Florida species is a burrower. The ma- 

 jority of species are to be found under bark, logs, stones and in 

 other dark, cool places. Some kinds of skinks have been observed 

 to guard the eggs by curling about them. Some old world species 

 are ovoviviparous. 



Family Amphishaenidae (worm lizards). — This highly modified 

 family is represented in the United States by one genus with one 

 species in Florida and another genus with one species in southern 

 California. Forty species are known from the American tropics and 

 others from northern Africa and the Mediterranean region. 



These remarkable lizards are all limbless except Bipes hiporus, 

 the two-footed lizard of Lower California, Avhich has the anterior 

 pair of limbs well developed. The skin is without scales and forms 

 numerous rings about the body, suggesting an annelid worm in 

 appearance. The eyes are absent or reduced. There is usually no 

 external ear opening. 



