2 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 73 



This paper is based upon the collections in the British Museum of 

 Natural Histor}^ London ; des Naturhistorischen Museums, Ham- 

 burg ; Zoologisches Museum, Berhn ; Museum d'Histoire Naturelle 

 de Paris ; California Academy of Science, San Francisco ; American 

 Museum of Natural History, New York City ; United States 

 National Museum, Washington, D. C; and the Museum of Compara- 

 tive Zoology, Cambridge, Mass., altogether a large and representative 

 series indeed. 



Two new species are described, one, Ctenosaura parkeri, from 

 Barranca Iberra, Jalisco, Mexico, is dedicated to H. W. Parker, 

 herpetologist, British Museum of Natural History, through whose 

 kindness the writer was enabled to examine the important types in 

 England. Two visits to the United States National Museum in 

 Washington made it possible to study the types there. The second 

 new species, clarlci, is dedicated to Dr. Herbert C. Clark, director of 

 medical research and laboratories. United Fruit Co., through whose 

 interest and efforts the various collections at the Museum of Com- 

 parative Zoology have been augmented from time to time. With the 

 exception of Cyclura (Ctenosaura) teres, which was described from a 

 living specimen, by Harlan in 1824, and of which there is no record 

 of its ever having been preserved, and Iguana (Ctenosaura) similis, 

 Gray, which was at one time in the Bell Museum, London, but subse- 

 quently disappeared, the type specimens of every form referred to the 

 genus have been carefully studied. 



To the following persons the writer wishes to offer his sincere 

 thanks for valuable aid in the preparation of this revision: Mr. H. W. 

 Parker, London; Dr. George Dunker, Hamburg; Dr. Ernest Ahl, 

 Berlin; Dr. F. Angel, Paris; Dr. L. Stejneger and Miss Doris M. 

 Cochran, Washington; Mr. J. R. Slevin, San Francisco; and Dr. 

 Thomas Barbour, Cambridge, Mass. 



ABBREVIATIONS 



M. C. Z Museum of Comparative Zoology, Cambridge, Mass. 



A. M. N. H American Museum of Natural History, New ifork, N. Y. 



U. S. N. M United States National Museum, Washington, D. C. 



Brit. Mus British Museum of Natural History, London, England. 



C. A. S California Academy of Science, San Francisco, Calif. 



M Male. 



F Female. 



A Adult. 



Y Young. 



H-grown Half grown . 



GENERAL CONSIDERATIONS 



The genus Ctenosaura includes 13 species of lizards, the distribu- 

 tion of which is confined to Mexico and Central America. In the 

 West Indian region their place is taken by the genus Cyclura, to 



