SOUTH AMERICA 379 



When Darwin visited Chatham Island in 1835 he found this 

 rice rat abundant. "It frequents the bushes," he wrote, 

 "which sparingly cover the rugged streams of basaltic lava, 

 near the coast, where there is no fresh water, and where the 

 land is extremely sterile." He seems to have made search for 

 it or other native rats on other islands, for he remarks that he 

 was unable to find it on other parts of the archipelago; nor has 

 any one since taken specimens. Indeed, Heller (1904), who 

 visited the island in 1898-99 and searched for it unsuccessfully, 

 believes "it is now probably extinct or else restricted to the 

 barren eastern part of the island where Darwin secured his 

 specimens." If it has really been extirpated, one may suppose 

 that the introduced brown and black rats have been too 

 active competitors. 



BAUR'S RICE RAT 



ORYZOMYS BAURI J. A. Allen 



Oryzomys bauri J. A. Allen, Bull. Amer. Mus. Nat. Hist., vol. 4, p. 48, May, 1892 

 ("Barrington Island," Galapagos group). 



The rice rat of Barrington Island, in the Galapagos Archi- 

 pelago, is believed to be very Closely allied to 0. galapagoensis 

 of Chatham Island but "differs mainly in having a somewhat 

 shorter tail and less yellow on the upper parts" (Heller, 1904). 

 The general color is said by its describer to resemble very much 

 that of the cotton rat, Sigmodon hispidus. A series of average 

 measurements given by Heller: Total length, 273 mm.; tail, 

 136; hind foot, 30-31; greatest length of skull, 31.5. 



This rodent is known only from Barrington Island, about 30 

 miles to the east of Chatham Island. Here Dr. George Baur 

 obtained the three specimens that served for the description of 

 the species a number of years ago. As Heller points out, the 

 lack of actual specimens of 0. galapagoensis makes close com- 

 parison out of the question, but there is every reason to believe 

 that it is distinct from the latter. Dr. Baur found it rather 

 common on Barrington, "between the bushes near the shore, 

 and also high up between grass and the lava rock." When 

 Heller visited the island ten years later, in 1898-99, he found 

 it "very abundant," inhabiting crevices among the loose lava 

 rocks and burrows and runways beneath bushes and brush 

 piles. "In habits it appears to be somewhat diurnal and was 

 as often seen at midday as at other times." Nothing further 



