The Striped Lizards or " Race Runners " 



streak over the ground. When the animal terminates its dash 

 for safety, it stops so abruptly that it seems to vanish. 



In the preparation of a resume of the species of Cnemi- 

 dophorus, the writer finds himself confronted by the most difficult 

 proposition of any yet encountered in this work. Provided 

 with a fine series of specimens, he has attacked the obstacle 

 from every side and with little success. For this genus he is 

 unable to construct a popular key and he will not presume to 

 offer any but concise descriptions of the alleged species. To 

 go into detail would be to construct descriptions that could 

 be comprehended only by the most advanced technical 

 worker. The definition of the species is the greatest puzzle of 

 North American herpctology. American writers have undoubt- 

 edly expended an excess of energy in naming species and sub- 

 species varieties. Single specimens have been provided with 

 full specific names and the descriptions have been founded upon 

 petty characters of pattern or scalation. Among lizards where 

 a certain amount of variation is marked, this course seems al- 

 together unwise. Foreign writers have worked in such extreme 

 opposition that a comparison of the two methods is quite be- 

 wildering. Nothing can straighten out this problem but the 

 work of some one who makes a specialty of the genus, gathers 

 about him elaborate series of all the species (?) and notes his 

 observations impartially. 



The student should remember, in examining the list that 

 follows, the characteristic of some species in retaining a striped 

 pattern through life, and the loss of the stripes and consequent 

 marbled or cross-banded pattern of others. 



The Cape Striped Lizard, Cnemidophorus byperytbrus, 

 (Cope). This, and the succeeding lizard, C. sericeus, may be told 

 from the other species by the scalation of the head. Behind the 

 central region between the eyes is a single plate, a condition 

 technically described as "frontoparietal plates fused together." 

 It has been employed to establish a separate genus Verticaria 

 of Cope. The other striped lizards have this plate divided. (See 

 illustrations). 



Colouration. Light brown or olive above; sides black. 

 Two yellow stripes on each side and two pale stripes on the 



185 



