Vol. I] VAN DENBURGH—SNAKES OF THE GALAPAGOS ISLANDS 335 



and Hood, should they now become connected and later sep- 

 arated again, is strongly suggestive. It might be thought to 

 point to an elevation and depression of Barrington and Inde- 

 fatigable subsequent to the general depression of the archi- 

 pelago. This view might be strengthened by the fact that 

 all of the snakes of South Seymour Island are striped. Certain 

 slight peculiarities of coloration, however, distinguish most 

 of the Barrington Island specimens from those of Indefat- 

 igable. With respect to these peculiarities, the striped snakes 

 of Barrington differ from the striped snakes of Indefatigable, 

 and agree with the spotted snakes from their own island. 

 Similarly, the spotted snakes of Indefatigable differ from the 

 spotted snakes of Barrington, but agree with striped specimens 

 from Indefatigable. Therefore, we must regard this as a 

 case of dichromatism, occurring in the snakes of these two 

 islands ; but if similar proportions hold in larger series, it will 

 be evident that specific differentiation has already begun, and 

 may ultimately lead to the formation of spotted and striped 

 races here as it has on Charles and Hood and on Albemarle 

 and Narborough islands. 



The following diagram will serve to show the probable 

 relationship of the snakes of the Galapagos. 



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