Vol. 1] VAN DENBURGH-GECKOS OF GALAPAGOS ARCHIPELAGO 409 



4 from Indefatigable 



8 " Daphne 



2 " James 



7 " Cowley 



2 " Duncan 



4 " Brattle 



5 " Tagus Cove, Albemarle 

 2 " Cowley Mt., Albemarle 

 10 " Iguana Cove, Albemarle 

 43 " southeastern Albemarle 



Obviously, this series of specimens is insufficient to enable 

 us to point out all the minor differences between the geckos 

 of these islands; but it does suffice to permit us to say that 

 all are closely related. From this we may conclude that these 

 islands all remained connected, and formed a single island, for 

 a long time after their separation from those islands already 

 considered, where distinct species have been evolved. 



While it is true that all these geckos from the central islands 

 are so closely related, they are not all identical. Those of 

 Duncan and Daphne islands differ sufficiently to enable us 

 to recognize them as distinct subspecies; from which we may 

 conclude that these two islands have had an independent insu- 

 lar existence longer than the others of the central group, which 

 doubtless remained connected until a still later period. 



Farther than this we cannot go, and it is evident that differ- 

 entiation in the geckos of the Galapagos Islands has progressed 

 neither so rapidly nor so far as it has in the case of the snakes 

 of the archipelago. The older and more stable organization 

 of these lizards has not changed so quickly. For this reason, 

 the geckos throw but little light upon the more recent history 

 of the islands. They, as it were, have not kept up to date. 

 Their story stops before the separation of Charles Island from 

 Hood, at a time when the central islands, excepting Duncan 

 and Daphne, yet were one. But so far as it goes, the story 

 of the geckos agrees completely with that of the snakes, except 

 on one minor point. Our study of the snakes indicated that 

 Barrington only recently became separated from Indefatigable 

 Island. The evidence afforded by the geckos would lead us to 

 place the separation of Barrington at a more remote period. 

 In other respects there is complete agreement. 



