CHAPTER XV : THE SPOTTED LIZARDS ; ZEBRA- 

 TAILED LIZARDS 



Small and Strictly Terrestrial Species of the Genera CALL1* 

 SAVRUS, VMA and HOLBROOKIA 



THIS chapter embraces a number of small, ground lizards 

 that live in dry and open places the plains, sub-arid regions 

 and the deserts. To match the pale sterile soil, their colours 

 are light; the pattern of none is rich in hues, though some 

 have the under side of the tail alternately barred with black and 

 white and such species when running, carry the tail curled over 

 the back, hence the popular title the Zebra-tailed Lizards. 



In the colouration, Callisaurus is precisely like Holbrookia 

 yellowish or grayish above, with two rows of darker, angular 

 blotches on the back, but these genera are separated by Uma, 

 -according to the structure. 



Outline of ihe Genera 



General Characters. Body rather stout; tail of moderate 

 length, scalation of the body and tail, above, fine and granular; 

 abdomen covered with larger, rounded scales. Top of the head 

 with numerous rounded scales not plates. Gray, yellowish 

 or green, with two rows of angular blotches. Usually one or 

 two ink-black spots on each side of the abdomen. Tail uniform 

 white beneath, or barred with black. 



I. Ear Drum Exposed. 



Toes long, without spiny fringes. Genus Callisaurus. 



Distribution. Deserts of the Southwest. 

 Toes long, with spiny fringes. GentJs Uma. 



Distribution. Deserts of the Southwest. 



II. Ear Drum Concealed Under The Skin. 

 Toes long, without spiny fringes. 



Distribution. Central and Western States. 



Genus Holbrookia. 



The Genus Callisaurus: A single species is recognised. 

 It is confined to the arid regions of the southwestern United 

 States and northern Mexico. 



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