OF THE BEAVER AND OF SOME SQUIRRELS. 1195 



tarsal area is covered with hair dovs^n to the plantar pad, and 

 there is no trace of metatarsal pads as in S. (Tamiasciurus) 

 hudsonicus. (Text-fig. 51, C, D.) 



This description of the feet of Eittaviias, based upon a single 

 individual, must not be taken as applying to all the species of 

 Tamias. In some dried skins of this genus in the Natural 

 History Museum, the digits appear to resemble those of Citellus 

 rather than of Sciurus and its allies in relative lengths ; and the 

 metatarsal area is not so extensively haired as in the specimen 

 of Eutamias described. 



e. Feet of the Brisily Grround Sqidrrels (Xerus, etc.). 



The feet of the African Ground Squirrels, Atlantoxerus getulus, 

 Xerus rutilus, Euxerus erythropus, and Geosciurits capensis difl'er 

 from those of the arboreal species hitherto described in having 

 the third digit the longest and the fourth only a little longer 

 than the second, so that the feet approach the perissodactyle 

 type ; the pollex is not suppressed to quite the same extent, but 

 stands away as a distinct excrescence from the antero-external 

 edge of the adjoining inner carpal pad, and this is not appre- 

 ciably produced distally beyond the outer carpal ; the metatarsal 

 area is naked to the heel, and its pads are either absent or poorly 

 developed. 



In Atlantoxems getulus the feet are long and slender and the 

 digits more nearly approach those of the arboreal Squirrels in 

 length, the third onlj^ slightly exceeding the fourth, which, in 

 the fore foot, is decidedly longer than the second. The lobes of 

 the plantar pads are large, well developed, the hallucal lobe on the 

 hind foot being nearly as large as the others individually ; the 

 carpal pads also are comparatively large, and the metatarsal pads 

 are at all events sometimes distinguishable, although small and 

 oval. (Text-fig. 52, A, B.) 



In Euxerus erythropus the fore foot is broader and shorter, 

 with respect both to the digits and sole, than in Atlantoxerus ; 

 the plantar and carpal pads are relatively smaller and the claws 

 are longer. The pollex is small but subcylindrical with a small 

 pad remote from the carpal. In the hind foot, too, the claws are 

 longer than in Atlantoxeribs, the lobes of the plantar pad are 

 considerably smaller, especially the outer and inner, the latter 

 being a small subcircular tubercle at the base of the hallux, only 

 about one-fourth the size of the median lobe ; and there is no 

 trace of metatarsal pads*. (Text-fig. 53, A, B.) 



In Geosciurus caj)ensis the feet are more robust and more 

 fossorial in character than in E. erythropus. In the fore foot the 

 three lobes of the plantar pad are well developed but shorter 



* X. rutihts is known to me only from a dried skin. On this the plantar lobea 

 appear to be somewhat larger relatively than in E. erjithropiis ; but there is no 

 trace of metatarsal pads, and the hallucal lobe of the plantar pad is small and 

 isolated. 



