7V 



THE GALAPAGOS TORTOISES. 



INTRODUCTION. 



A warm interest of the Museum authorities in the Giant land tortoises has 

 led to the acquisition of so many notable specimens, through liberal exchanges 

 and purchases, as to demand a revision of portions of the collection, especially 

 of that portion directly pertaining to the Galapagos Archipelago. This forms 

 the reason for the following article. It is based mainly on partial specimens, 

 i. e., carapaces and sternums, but it is thus that these tortoises are most generall}' 

 known, thus that they are most widely, and most commonly represented in 

 descriptions, figures, and collections. A few attempts have been made at 

 complete characterization of the species by including the anatomical features; 

 these were founded on single specimens, and the individuals of the species are 

 found to differ too much to admit of accurate distinctions unless confirmed by 

 averages secured from repeated dissections, for which much of the material and 

 the labor has yet to be supplied. 



The Galapagos Islands form an isolated group in the eastern Pacific on the 

 equator about 6° west of Ecuador, or in other words, they are situated between 

 89° and 92° of west longitude and between 1° 30' south and 2° north latitude. 

 The largest of them is about eighty miles long and at its widest is about fifty 

 miles wide; from this the sizes vary to some that are mere points of rock or 

 shoals. They are separated from the mainland by more than four hundred 

 miles of deep sea, a thousand fathoms or more in depth. The wide separation 

 from the continent, their considerable distances from one another, with great 

 differences in altitudes and consequent variations in climate and fertiUty give 

 them exceptional attractions in the eyes of naturaUsts. Here if anywhere they 

 might hope to find the species of the flora and fauna distinct from those of the 

 world around them and here it might be possible to trace their development and 

 derivation. Questions of origin go back to the advent of the islands themselves ; 

 neither in case of lands, plants, nor animals have the questions been answered 

 with any great degrees of satisfaction. Some authorities have decided that the 

 islands are oceanic, that they never were connected with the continent, but 

 were pushed up from the sea-bottom by the numerous volcanoes they contain. 



