ALLEN: MAMMALIA OF SOUTHERN PATAGONIA. 3 



tinuously at camps in the Basalt Canons, a pampa country having an 

 altitude of about 3,000 feet. A few specimens were collected near Swan 

 Lake, some fifty miles to the southward, in March, but none were taken 

 after May 15, during the return journey to the coast. Hence nearly all 

 of the 200 specimens collected by Mr. Colburn.were taken in March, 

 April, and the first half of May, or during the season corresponding to 

 fall in northern latitudes, and in the elevated pampa country, at the east- 

 ern base of the Andes, between the mouth of Rio Belgrado and Lake 

 Buenos Aires. This collection is the property of the Princeton Univer- 

 sity, except a series of the duplicates which has been presented to the 

 American Museum of Natural History. 



The coast material is especially important as containing practically topo- 

 types of a number of Waterhouse's species of Muridae, based on specimens 

 collected by Darwin during the voyage of the " Beagle." The sub-Andean 

 series represents a wholly new field, and, as might be expected, contains 

 forms allied, on the one hand, to species previously known only from 

 Tierra del L^uego, and on the other, to species described from Mendoza, 

 nearly a thousand miles to the northward. A number of these prove to 

 be new, though not widely different, respectively from their northern or 

 southern allies. 



In attempting to work up this material — the first collection of mammals 

 of any magnitude ever received in this country from Patagonia — it was 

 recognized at the outset that it would be of the utmost importance to make 

 direct comparison of the species represented in it with the types and other 

 authentic material from the same general region contained (almost exclu- 

 sively) in the British Museum, in which are the types of Bennett's and 

 Waterhouse's species, described more than a half century ago, and the 

 types of Thomas's more recently described species from northern Argen- 

 tina and Paraguay. Accordingly a good series of specimens was taken to 

 London during the summer of 1 901, and through the kindness and cordial 

 assistance of Mr. Oldfield Thomas, Curator of Mammals at the British 

 Museum, I was able to make the necessary critical comparisons with the 

 historic material relating to South American Mammalogy contained in this 

 great Museum. Following the custom of earlier days, the Bennett and 

 Waterhouse types were exhibited for many years as mounted specimens, 

 and thus through long exposure to light suffered much deterioration, but 

 they are still, of course, invaluable as standards of reference. 



