1867.] MR. ST. GEORGE MIVART ON THE LEMURID.E. 965 



Fig. 4. 



^.H ^ ^'' 'tis/ 



Chvirogakus furcifer. Scale twice nat. size. 



As regards the tarsus, however, there is a great difference, as the 

 following dimensions show : — 



inches. 



Extreme length of the tibia 2*40 



Extreme length of the cuboides 0'27 



Extreme length of the os calcis 0*74 



Length of dorsum of naviculare 0"36 



Length from proximal end of calcis to distal end of 



naviculare 0"90 



Length of astragalus 0"37 



Breadth of os calcis and naviculare, measured across 

 their narrowest part 0*22 



Thus, instead of the dorsum of the naviculare being a little less 

 than half the extreme length of the astragalus, it nearly equals it ; 

 while the latter bone is only half the length of the os calcis, instead 

 of being equal to about two-thirds of its length ; moreover the cuboid 

 is considerably shorter than the dorsum of the naviculare, instead 

 of being somewhat longer than the latter. In all these respects the 

 tarsus of C. furcifer closely resembles that of M. pusillus*, and 

 differs widely from the tarsus of C. milii. The distinction therefore 

 between Cheirogaleus and Microcebus, based upon tarsal structure, 

 falls to the ground, unless C. furcifer be placed (as I placed in 

 1864-r) in the latter genus along with M. pusillus and M. myoxinus. 

 But since I have examined the skin and skeleton of C. milii I can 

 no longer be satisfied with such an association, as there can, I think, 

 be no doubt but C. milii and C furcifer are very closely allied 

 forms. 



It will nevertheless be possible (and perhaps even useful) still to 

 retain, provisionally at least, the distinction between Cheirogaleus 



* A8 I anticipated that on investigation it would turn out to do (P. Z. S. 

 1864, p. 623). 



t Guided by its apparently elongated foot, as seen in the mounted skin in the 

 British Museum. 



