250 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



must represent one of two very similar races. These races 

 are the one characteristic of Indefatigable Island, and that 

 found upon Cowley Mountain in central Albemarle. The ques- 

 tion then arises, to which of these can the name Testudo ni- 

 grita be applied. 



The differences between the Cowley Mountain tortoise and 

 those of Indefatigable are very slight. Indeed, there is no 

 measurement of the former which cannot be duplicated in 

 some specimen from Indefatigable Island. However, the 

 curved length and the width between second and third mar- 

 ginals are less, and the middle height and difference between 

 curved length and curved width are greater, than is usual in 

 the Indefatigable tortoise. If we take, then, the percentages 

 of these measurements and add the first two (the curved 

 length plus width at second to third marginals), and subtract 

 from this the sum of the other two measurements, we have 

 as the result 111, a figure which always is exceeded when we 

 combine in the same way the measurements of any Indefatiga- 

 ble tortoise. 



The fact that I have only one tortoise from Cowley Moun- 

 tain, of course, renders unsafe the conclusion that we have 

 here two distinct races; but, on the other hand, the fact that 

 my 23 specimens from Indefatigable all are alike in this dif- 

 ference from the Cowley specimen gives that conclusion con- 

 siderable weight. 



Unfortunately, we cannot know the middle height of Giin- 

 ther's specimen, but the other measurements enable us to say 

 that it agreed with the Indefatigable tortoises and was unlike 

 the Cowley specimen, unless it had a middle height greater 

 than in any other specimen of any race of Galapagos tortoise. 



We seem justified, then, in saying that Giinther's Testudo 

 nigrita agrees with the Indefatigable tortoise. When, in ad- 

 dition, it is recalled that the early tortoise-hunters frequented 

 Indefatigable Island, but rarely visited Albemarle, I can see 

 no good reason for doubting that this specimen really came 

 from Indefatigable, and that it belongs to the race which re- 

 cently has been called Testudo porteri. However, since con- 

 clusions based upon an imperfect specimen of unknown origin 

 must always be open to some question, and especially since 

 this specimen is not the original type upon which the name was 



