68 



NORTH AMERICAN FAUNA. 



collected which is peculiar to these islands. The species has been 

 recorded from the mainland (by Van Denburgh, Proc. Phila. Acad., 1897, 

 p. 463, who identifies "a large number of lizards from Mazatlan, San 

 Bias, and Tepic" with Giiuther's species), but I am satisfied that these 

 records are based upon specimens of C. gularis mexicanus (Peters) 

 which superficially very much resemble the island species. The mis- 

 identification is probably due to the fact that Cope, in his monograph 

 of the genus, overlooked the different keeling of the caudal scales 

 which is the essential character of this species. 



List of specimens of Cnemidophorus mariarum. 



Cnemidophorus gularis mexicanus (Peters). 



The Isabel Island swifts are identical with the mainland form, two 

 specimens of which were brought from San Bias. They are quite dis- 

 tinct from the species on the Tres Marias, which is well characterized 

 by the smaller femorals and the parallel caudals. It is strange that 

 Cope, having had the latter character clearly pointed out by Boulenger, 

 should have referred G. mariarum to C. gularis as a subspecies. 



List of specimens of Cnemidophorus gularis mexicanus. 



