Vol. II, Pt. I] VAN DENBURGH— GALAPAGOS TORTOISES 



301 



General remarks. — This is a "saddle-backed" tortoise with 

 the anterior marginal plates very strongly reverted. It seems 

 most nearly related to Testudo becki of northern Albemarle, 

 but no such enlargement and outward and backward devel- 

 opment of the anterior marginals is seen in any other tor- 

 toise. The early voyagers did not report the presence of 

 tortoises on Narborough Island, so the discovery of this spe- 

 cies was rather unexpected. 



Field Notes.— Leaving Tagus Cove, April 2, 1906, Mr. Beck 

 and Mr. Hunter set out for Narborough to hunt for tortoises. 

 The climbing of the volcano proved most arduous, but Mr. 

 Beck, leaving Mr. Hunter at the lower level, pushed on to the 

 rim of the crater. The story of the finding of the only tortoise 

 known to have been taken upon this island is told by Mr. 

 Beck as follows : 



Starting, at daylight on April 3, 1906, a point about one- 

 half the distance to the top of Narborough Island was 

 reached at noon. Here commenced a narrow "island" of 

 lava of more ancient eruption than that over which the firsi 

 stage of the journey was made. This "island" had scattering 

 cactus and a few bushes and vines. As I worked up through 

 this strip of lava I saw a few old droppings of a tortoise, and 

 on examination I found he had been eating a considerable 

 quantity of Cereiis, a cactus that is not often attacked by other 

 tortoises, as the spines are much more difficult to make way 

 with.. Many spines were found in some of the excrement. 

 Thinking that if a tortoise were down in this desolate patch, 

 there would be many on top, I climbed toward the top, stopping 

 on the way at one small mount of much older larva, seemingly 

 of about the same age as Tagus Cove Mountain, for there 

 was considerable soil. There were no signs of tortoises here, 

 though iguanas were plentiful. Reaching the base of the 

 main crater at about 5 o'clock, I camped, and next morning; 

 climbed up to the top, which was, where I climbed, a plateau 

 a half mile across to the edge of the crater. The crater was 

 probably over 1000 feet deep and a half mile in diameter. 

 The plateau was covered with rank grass with clumps of 

 Opuntia near the outer edge and scattering Cereus — an excel- 

 lent place for tortoises; but none was seen, nor any signs. 



