REPTILES OF THE TRES MARIAS ISLANDS. 



67 



Sceloporus boulengeri Stejueger. 

 N. Am. Fauna No. 7, 1893, p. 180, pi. I, figs. 5a-c. 



This species appears to be smaller than 8. clarkii, of whicb it is the 

 southern representative. A full-grown male (No. 634e) measures only 

 yoiiim f rom snout to vent. 



Van Deuburgh's belief that 8. boulengeri "is the same form as Cope's 

 AS. oliyoporus" (Proc. Phila. Acad., 1897, p. 463) is not well founded. The 

 latter is easily distinguished by having only 2 to 3 femoral pores, besides 

 other differences. It is probably identical with 8. horridus. 



Ciiemidophorus mariarum Giinthrr. 



Ciifinidophonis mariarum Giinther Biol. Cent. -Am., Rept. p. 28, pi. XX, April, 1885; 

 Boulenger, Cat. L5/ards, Brit. Mus., p. 368, 1885. 



The swifts from the Tres Marias are essentially alike. Those from 

 Maria Mad re are the largest and possibly also most distinctly marked ; 

 those from the small detached rock off the west side of Maria Cleofa 

 as well as the one from the main island of that name are somewhat 

 smaller. According to Mr. kelson's observation those from the detached 

 islet, which is a bare rock, the nesting place of numerous sea birds, 

 appeared to him paler when alive than those on the other islands, but 

 now, in alcohol, the difference, if any, is very slight. 



This species, which was originally described by Giiiither from speci- 

 mens collected by Forrer on the Tres Marias seems to be confined to 

 this group of islands. If so, it is the only species of reptile hitherto 



