CLASS REPTILIA 557 



red and black. A large specimen measures a foot and one half 

 in length. Gila monsters possess grooved fangs on the lower 

 jaw, and, when fighting, viciously grasp their prey and throw 

 themselves on their back, thus allowing the poison to flow down 

 into the wound. The bite is fatal to small animals and dan- 

 gerous to man. 



Family AMPHISB^ENID^:. - - WORM LIZARDS. - - These are 

 limbless, burrowing lizards resembling worms in appearance. 

 There are about ten genera and sixty species known from both 

 the Old and New Worlds. Of these only one, the Florida worm 

 lizard, Rhineura floridana, is found in the United States. This 

 species is restricted to the Florida peninsula. It is about eight 

 inches long. 



Family LACERTID.E. - - TYPICAL OLD-WORLD LIZARDS. - 

 There are seventeen genera and about ninety-six species of 

 lizards that are included in this family. They all possess well- 

 developed limbs, and a long, fragile tail. The green lizard, 

 Lacerta viridis, is a species common in central and southern 

 Europe. Lacerta vivipara of Europe is viviparous. 



Family SCINCID^E. -- SKINKS. - -The skinks are found in 

 many parts of the globe. In North America there are two 

 genera and fifteen species. Ettmeces quiiiijuclineatus, the five- 

 lined or blue skink, is the species common in the Eastern 

 and Central states. The young are black with a longitudinal 

 yellow stripe on the back and two on either side, and a blue tail. 

 The females " retain dull stripes through life, but the males 

 become uniform, dull olive-brown on the body and bright red 

 about the head." This color change has been the cause of several 

 specific and common names. The length of this skink is about 

 nine inches. 



Suborder 3. SERPENTES. -- SNAKES. - -The snakes resemble 

 the lizards and chamejeons in many of their anatomical features. 

 They differ from them in at least four respects: (i) the right 

 and left halves of the lower jaw are not firmly united, but are 

 connected by an elastic band; (2) there is no pectoral girdle; 



