490 8. TEIIDM 



latter, slender and provided with large scales, which are 

 keeled above but smooth below. The eye has well devel- 

 oped lids and a round pupil. Large ear-openings are pres- 

 ent. One strong and several weaker folds cross the throat. 

 Femoral pores are present. 



In many of the species of this genus the color pattern 

 changes with increasing age of the individual. The young 

 are marked longitudinally with light stripes on a dark 

 ground. With increasing age, spots appear in the dark 

 interspaces between the light stripes. These spots increase 

 in size until they extend to the light lines and form little 

 irregular cross-bars. In still older individuals the light 

 lines become indistinct or obliterated, and the dark and light 

 spots extend transversely and unite with others to form 

 more or less irregular cross-stripes or bars, in this way the 

 direction of the markings is changed from longitudinal to 

 transverse. These changes have not always progressed to 

 the same stage in individuals of the same size. We do not 

 know whether such specimens are of the same age or not, 

 but, however this may be, the changes in pattern seem to 

 follow one another in more or less constant order. A few 

 species never show the longitudinally striped style of color- 

 ation, some retain it throughout life, and some others do 

 not develop fully the transverse markings. 



Synopsis of Species and Subspecies 



a. — Posterior surface of forearm with some series of en- 

 larged scales or granules j not covered with granules of 

 equal size. 

 b. — A few rows of moderately enlarged granules on back 

 of forearm. 



