The Spotted Lizards; Zebra-tailed Lizards 



development of the feet. Along the inner and outer margin 

 of most of the toes, is a fringe of flat spines; this character is 

 seemingly Nature's -provision to aid these lizards in rapidly 

 traversing the desert sands; to assist in this arrangement, the 

 under portion of each claw is hollowed out cup-like and has 

 sharp edges. The same development is found with some of 

 Old World desert geckos. It is interesting to find such pro- 

 nounced examples of adaptation, on exactly similar lines, in 

 forms so far removed from one another both in classification 

 and habitat. Similar conditions have been described under the 

 head of the Horned Rattlesnake, Crotalus cerastes. 



Following is a key to the species of Uma, embracing some 

 of the definitions of Cope, who named three of these lizards. 



I. Two black crescents on throat; a black spot on each 

 side of abdomen. 



Blackish, covered with pale and perfectly round 

 blotches, the borders nearly touching; in the centre 

 of each disk is a black spot. Abdomen white, with a 

 black spot on each side. Two black crescents on throat, 

 their points directed forward. Length about 8 inches; 

 head and body, 4 inches. 



ROUND-SPOTTED DESERT LIZARD, Uma scoparia, Cope. 

 Distribution. Has been found near Tucson, Arizona. 



II. No black crescents on throat; a black spot on each 

 side of abdomen. 



Brownish, with black, longitudinal lines; the brown 

 between the dark bands often broken up into rounded 

 blotches, each containing a reddish spot. A large, 

 black spot on each side of the abdomen ; throat with 

 narrow, black, longitudinal lines. Length about 7^ 

 inches. 



RED-SPOTTED DESERT LIZARD, Uma rufopunctata, Cope. 

 Distribution. Deserts of southern California, south- 

 western Arizona and Lower California. 

 Colouration above, like U. scoparia. Abdomen^ white 

 with a black spot on each side; chin and throat with 

 a few blue or black spots. 



OCCELLATED DESERT LIZARD, Uma notata, Baird. 

 Distribution. Mohave Desert, Arizona. 



III. No black spots on abdomen, or black crescents on throat. 

 Greenish, with darker spots. No black spots on the 



the abdomen ; seven black spots on under surface of 

 tail. 



COPE'S DESERT LIZARD, Uma inornata, Cope. 

 Distribution. Colorado Desert. 

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