974 MR. ST. GEORGE MIVART ON THE LEMURID^. [DeC. 12. 



Galago. I find in G. crassicaudatus the dimensions to be as 



follows : — . , 



inches. 



Length of tibia 3-40 



of tarsus 1 '65 



of OS calcis 1 ■2.T 



of cuboides 0*40 



from proximal end of os calcis to distal end 



of cuboides \'^0 



of astragalus 0*59 



of dorsum of naviculare 0*71 



Least transverse dimensions of both os calcis and na- 

 viculare 0*33 



I am not disposed to consider the elongated tarsus of C furcifer 

 a sign of any really close affinity between that form and Galago ; 

 for a still more elongated tarsus distinguishes the genus Tarsius 

 (remote enough from either Cheiroffaleus or Galago), and the Cheiro- 

 galei, so closely allied in other respects, differ greatly in the propor- 

 tions of this part. Moreover the distinction as to geographical dis- 

 tribution between Cheirogaleus and Galago is very striking, although 

 it may be remarked that C. furcifer is an inhabitant of the west coast 

 of Madagascar. Finally, the difference which, according to Dr. Peters, 

 exists in the position of the gall-bladder must not be forgotten. 



It is interesting to note the great variation as to tarsal structure 

 exhibited by these nearly allied species from Madagascar, compared 

 with which the differences exhibited by the various species of Galago 

 are quite trivial. There are overwhelming reasons for believing that 

 in Madagascar we are near (or at least probably nearer than in any 

 other land now above the sea-level) to the locality where the original 

 forms of the whole suborder Lemuridea first arose. Subsequent mo- 

 difications, however, such as the exaggerated tarsus now found only 

 in Africa on the one hand, or in Borneo and Celebes on the other, 

 might have arisen in some more or less remote locality. The co- 

 existence, however, of closely allied forms, in Madagascar, differing 

 so much from one another in tarsal structure, seems to me to indi- 

 cate that this peculiar conformation of the tarsus (unknown in any 

 other group of animals) also took its rise in the same region, and 

 that modified descendants, diverging east and west, there carried still 

 further this remarkable peculiarity, which culminates, and is accom- 

 panied by the maximum of lemurine abnormalities, in the most 

 remote region to which any species of the Lemuroidea has, as far as 

 yet known, ever extended. 



The inflation of the mastoidal region of the periotic, which causes 

 Lepilemvr to differ from the other Lemurince, and assimilates it to 

 Galago, is not, I think, a character of any great importance. It 

 exists in the Nycticebina as well as in Galago ; and in the genus 

 Indris an enlargement above the posterior root of the zygoma (which 

 seems to answer to the mastoidal swelling of Galago) is present in 

 /. laniger, while it is absent in /. hrericaudatus*. 



» P. Z. S. 18(i(>. p. 160. 



