XIII 



PHYLUM CHORDATA 



495 



Fin. 1109.— Rock Wallaby (Petrogale xanthopus). (After Vogt and Spscht.) 



The first and fifth digits of the fore-feet are vestigial or absent, the 

 remaining three nearly equally developed. In the hind-foot the 

 fourth toe is much longer and stouter than the others, while the 

 second and third are small and slender and united together by a 

 web of skin, and the first is vestigial or absent. The marsupium 

 has its opening directed backwards. 



Fio. 1110.— niarsupial Mole (Notoryctes ti/phlops). (From the Cambridge Natural Eistoiij.) 



Notorydes, the Marsupial Mole (Fig. 1110), is a small, burrowing 

 Marsupial, with short and powerful limbs, each with five toes. 



