59.81,1 (72.2) 



Article X.— DIAGNOSES OF TWENTY-THREE NEW SPECIES 



AND A NEW GENUS OF LIZARDS FROM 



LOWER CALIFORNIA 



By M. C. Dickerson 



This preliminary statement of diagnoses of new species precedes a 

 larger preliminary paper on the lizard fauna of Lower California and the 

 Southwest, which will include descriptions and discussions, illustrations, 

 reviews of various genera, with maps and keys. 



The twenty-three species presented here are based on material col- 

 lected by the Albatross Expedition to Lower California in 1911, under the 

 auspices of the United States Bureau of Fisheries and The American 

 Museum of Natural History. The types are to be deposited in the 

 United States National Museum. 



Among the forms represented, some are species of great distinct- 

 ness, more or less remote from all other known forms, such as the two 

 species of Sauromalus from San Esteban and La Paz; others, like the 

 two Ctenosauras from San Esteban and Cerralvo, are species by island 

 isolation, restricted to their type localities, and showing relatively close 

 relationship with well-known mainland forms. The two species intro- 

 ducing the new genus Sator are primitive forms of considerable interest 

 in the phylogenetic history of the Iguanidse. 



1. Ctenosaura conspicuosa, 1 new species 



Type.— A. M. N. H. No. 5027, <?. Collector, C. H. Townsend, Albatross Expedi- 

 tion, April 13, 1911. 



Pakatypes.— A. M. N. H. Nos. 5640 9, 2278, 2693, 2695, 5639. 



Type Locality. — San Esteban Island, Gulf of California, Mexico. 



Diagnosis. — Closely related as shown by scutellation to Ctenosaura hemilopha 

 Cope, of the Cape Region. Size extremely large, total length exceeding 650 mm. 

 in the large males, for which the following characters are diagnostic: series of high 

 scales of the crest ending more or less abruptly at a point opposite the middle of the 

 adpressed upper arm, the small keeled scales which continue along the vertebral line 

 traceable to various points beyond the middle of the body and anterior to the rump; 

 scales of dorsal tibia with strong sharp keels and spines, of dorsal foot with strong 

 spines; tail spinous dorsally and laterally throughout its length; enlarged scales in 

 the posterior rows of the caudal whorls (first half of tail) only moderate in size, length 



'Because of its yellowish white color, this giant lizard is very conspicuous on the rocka of San 

 Esteban, as is also the big yellow Sauromalus (S. varius, new species). 



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