58 MANUAL OF NATURAL HISTORY. 



those of sides like those of back. Legs 4, 

 strong. Toes 5-5, compressed, unequal. — 

 Thighs poreless. 



2. Family.— Caltetepons (Helodermidse). Head de- 



pressed ; head-shields many-sided, convex ; 

 muzzle rounded ; femoral pores none ; scales 

 of back and sides oblong, 6-sided, very convex ; 

 of belly oblong, rather convex ; tail round, with 

 oblong convex scales above, and flat, elon- 

 gate, thin plates beneath; legs 4, strong; 

 toes 5-5, curved. 



B. Head with large, regular shields. Tongue mostly 

 free at base. 



3. Family. — Teguexins (Teidse). Head pyramidi- 



cal: shields regular, many-sided ; teeth solid, 

 rooted ; tongue free, elongate, flat ; scales of 

 back granular or keeled, rhombic ; sides flat, 

 scales small, granular ; throat scaly, with a 

 double collar. 



4. Family. — Lizards-proper (Lacertidse). Head pyra- 



midical ; shields regular, many-sided ; throat 

 scaly, often with a cross fold in front, and a 

 collar of larger scales behind ; tongue elon- 

 gate, flat, long-forked ; teeth hollow, rooted ; 

 scales granular or rhombic, keeled ; sides 

 : flat, scales small, granular. 



5. Family. — Cordyles (Zonurid^e). Head pyramidal 



or depressed; shields regular, many-sided; 

 tongue flat, nicked at tip ; scales of back 

 and tail large, rhombic ; sides with a distinct 



