326 



THE HIND FOOT OR PES. 



[chap, 



The insect- and root-eating, ground-dwelling Bandicoots 

 {PeramelidcE) differing in many other respects from the 

 Kangaroos, have their hind-foot constructed on exactly 

 the same type as in Maavpus, even to the relative length 

 of the clifferent digits, though there is often a rudiment of 

 the metatarsal of the hallux. In one 

 remarkable genus {C/ioeropns), already 

 mentioned on account of the peculiar 

 structure of the manus (see Fig. 104, 

 p. 281), the same type is carried to a 

 great extreme, the fourth toe (see Fig. 

 124) remaining of a prodigious size 

 and the fifth being reduced to even 

 smaller dimensions than the second or 

 third. 



MoNOTREMATA. — In both species 

 the seven usual bones of the tarsus are 

 complete and distinct,^ and the five 

 digits have the normal number of pha- 

 langes. 



In the Ornithorhynchus the proximal 

 articular surface of the astragalus is 

 divided by a deep groove into two 

 distinct heads, one for the tibia, and 

 the other for the fibula, the latter 

 being the larger of the two ; the inner side has a cup- 

 shaped socket, into which fits an incurved conical process 

 from the low^er end of the tibia. The tuberosity of the caj- 

 caneum is broad and bifid at the extremity, and directed 



vj. 



Fic;. 124. — Bones of right 

 foot of Cliocropns casta- 

 notis ^nat. size). 



^ It has been stated that the cuboid in the Ornithorhynchus is divided 

 into two bones, as in some reptiles, one supporting the fourth and the 

 other the fifth metatarsal ; but this is not the case in any specimen 

 which I have examined. 



