678 Bulletin American Museum of Natural History [Vol. XL VI 



Conclusions on the development of the peculiar coloration of dis- 

 parilis from the still more distinctive pattern of C. martyris and C. cata- 

 linensis are therefore baseless. An adequate understanding of the rela- 

 tions of the fifteen species of Cnemidophorus in the present list can only 

 be reached by the comprehensive study of large series of each species, 

 which are not at present available. 



Cnemidophorus martyris Stejneger 



Cnemidophorus martyris Stejneger, 1891, p. 407; Stejneger and Barbour, 1917, 

 p. 66. 

 Range. — San Pedro Martir Island, Gulf of California. 



Cnemidophorus catalinensis Van Denburgh and Slevin 



Cnemidophorus catalinensis Van Denburgh and Slevin, 1921c, p. 396. 

 Range. — Santa Catalina Island, Gulf of California. 



Two specimens (A. M. N. H. Nos. 6884-85), without other locality 

 than "Lower California," referred to C. disparilisby Dickerson, almost 

 certainly belong to this species, as has been noted above. 



Cnemidophorus dickersonse Van Denburgh and Slevin 



Cnemidophorus dickersonse Van Denburgh and Slevin, 19216, p. 97. 



Range. — Confined to Isla Partida, near Angel de la Guardia Island, Gulf of 

 California. 



Cnemidophorus canus Van Denburgh and Slevin 



Cnemidophorus canus Van Denburgh and Slevin, 19216, p. 97. 

 Range. — Sal Si Puedes Island, Gulf of California. 



Cnemidophorus bacatus Van Denburgh and Slevin 



Cnemidophorus bacatus Van Denburgh and Slevin, 19216, p. 97. 

 Range. — San Pedro Nolasco Island, Gulf of California. 



Key to the Species of Cnemidophorus in Lower California 

 (Exclusive of Insular Forms) 



1. Postmental little if at all longer than the mental; parietals subequal in length 



to the fronto-parietals; size very large C. maximus. 



Postmental longer than mental; parietals decidedly longer than the fronto- 

 parietals; size moderate 2. 



2. Tail red distally ; dorsal pattern of sharply defined black spots, in regular longi- 



tudinal and transverse rows C. rubidus. 



Tail not red at end; dorsal pattern of longitudinal lines or rows of spots, not 

 in regular transverse rows 3. 



3. Granular scales between collar and enlarged central gulars very small, abruptly 



differentiated from the latter C. bartohmas. 



