ALLEN: mammalia: caviid/e. 25 



drowning such of its inhabitants as were caught below, or driving them 

 to seek refuge by escaping from the burrow where they were certain to 

 meet with a similar death from the downpour of rain on the outside. As 

 I walked about this morning considering the destruction wrought by the 

 storm of the previous night, I was struck with the great importance of the 

 work accomplished by rodents and other burrowing animals, when con- 

 sidered as agents of erosion, and it appeared to me that this source of 

 erosion had not been given sufficient attention in our text books of geology, 

 when treating of the various erosive agents." 



Family CAVIID^. 

 Kerodon australis (Is. Geoftroy). 



(Plate VII, Fig. I, Skull.) 



Cavia aitstralis Is. Geoffroy-St. Hilaire, Guerin's Mag. de Zool., 1833, CI. 



1, pi. xii, animal. Northern Patagonia. — D'Orbigny, Voy. dans 

 I'Amer. Merid. Mamm., 26, pi. xviii, figs. 1-4. — Thomas, P. Z. S., 

 1898, 211. Chubut, E. Patagonia. — Hatcher, Narrative Princeton 

 Univ. Patagonian Exped., I, 1903, 123, habits. 



Cavia [Cerodon) austyalis Waterhouse, Mamm., II, 1848, 180, pi. iii, fig. 



2, animal, pi. xvi, fig. 13, skull from below. 



Cavia \Aneoma\ australis Burmeister, Descrip. phys. Rep. Argent., Ill, 



1879, 272. 

 Kerodon kingii Bennett, P. Z. S., 1835, 90, Port Desire, Patagonia. — 



Waterhouse, Zool. Voy. Beagle, Mamm., 1839, 88. — Trouessart, Cat. 



Mamm., ii, 1897, 639. 

 Adult (March- May). — Above dark yellowish gray, finely varied with 

 black ; sides lighter, less varied with black-tipped hairs ; ventral surface 

 white with a slight yellowish tone, varied more or less with gray, through 

 the showing more or less at the surface of the dull gray underfur ; sides 

 of nose, a narrow eye ring, and the space between the eye and ear yellowish 

 gray, or buffy white, with a postauricular patch of pale buff; ears thinly 

 clothed, the very short hairs yellowish gray on both surfaces; upper sur- 

 face of feet pale yellowish gray, the toes lighter, clear pale buff; toe pads 

 and callosities blackish. 



Young. — Scarcely at all different from the adults, and, like the adults, 

 different specimens vary from yellowish white to mottled grayish white 

 below. 



