48 HELLER 



which are said to be nearly indistinguishable. Boulenger^ 

 places it near Iguana. 



The marine Iguana A7nblyrhynchiis is closely allied to Cono- 

 lophus, of which it is perhaps a marine form evolved, as sug- 

 gested by Garman, on barren islands where vegetation was 

 lacking, thus compelling an alga diet or extermination. 



The single species and subspecies oi Dromicus are both closely 

 allied to D. chamissonus of Peru and Chile from which species 

 the Galapagos snakes are doubtfully distinct. 



The author is under obligations to Dr. C. H. Gilbert, of Stan- 

 ford University, in whose laboratory the work has been done, and 

 to Mr. J. O. Snyder, curator of the Leland Stanford Junior Uni- 

 versity Museum, for many favors received in the handling of 

 the collections. 



SYSTEMATIC ACCOUNT. 



Genus Chelone Brongniart. 

 Chelone Brongn., Bull. Soc. Philom., il, p. 89, 1800. 



Range. — Cosmopolitan in tropical and subtropical seas. 



CHELONE MYDAS (Linnaeus). 

 Testudo mydas Linn., Sys. Nat., ed. 10, i, p. 197, 1758. 



Range. — Tropicopolitan. 



Common among the islands of the Galapagos Archipelago. Most 

 abundant in the shallow lagoons and on the sand beeches where the 

 females come to deposit their eggs. 



The crew secured many tui-tles for food and we observed many 

 others on the beaches. The coloration of the upper parts varied from 

 dark greenish to brownish-red, the reddish coloration greatly predom- 

 inating- in Galapagos specimens. Only one adult specimen was pre- 

 served. 



The turtles have been driven from some of the islands, on which 



dogs and pigs have been introduced, by the ravages of these animals 



on their eggs and breeding grounds and also by Indians who hunt 



them for their oil. They are, however, still abundant about Albemarle 



and Narboro. 



Genus Testudo Linnaeus. 



Testudo Linn., Syst. Nat., ed. 10, i, p. 197, 1758. 



Range. — Ethiopian, Oriental, Mediterranean, Neotropical (east of 



the Andes) and South Temperate Nearctic. 



' Boulenger, Cat., 11, 1S85, p. 186. 



