962 MR. ST. GEORGE MIVART ON THE LEMURID.E. [DeC. 12, 



it true that there is in C. milii, as De Blainville remarks*, a certain 



elongation of the astragalus as compared with the other tarsal bones, 



but the naviculare is quite short comparatively, instead of being 



much elongated as it is in M. pusUlus. Indeed, in the latter species, 



the naviculare is absolutely as well as relatively longer, although in 



it (i. e. in M. pusillus) the length of the dorsal and lumbar regions 



together is only 2'7o inches, while the same part in C. milii is 



5 inches in length. 



° C. mint, M. pvsmus. 



inch. inch. 



Length of cuboid "21 *16 



— ■ of OS calcis "52 '36 



of dorsum of naviculare .... '\7 '20 



of astragalus *3.5 '20 



The dimensions of the tarsal bones of M. myoxinus are almost the 

 same as those of M. pusillusf. In addition to this distinction in 

 the tarsus, the palate has no defects of ossification in C. milii ; the 

 fifth cusp of the hindmost lower molar is rudimentary, instead of 

 being distinct ; there is a small malar foramen, while in M. jmsillus 

 there is none. The carotid foramina on the basis cranii are also 

 very conspicuous, instead of being almost hidden by the auditory 

 bullae ; the pterygoid fosss are also larger ; and, lastly, the first 

 upper premolar is slightly caniniform and considerably longer than 

 the second one, instead of being smaller and slightly shorter than 

 the second one as in M. pusillus. 



On the other hand, C. milii agrees with M. pusillus in having the 

 palate prolonged, the posterior palatine foramina large, a distinct 

 interparietal bone, in the absence of any enlargement of the mastoidal 

 region of the periotic, and in the other characters before assigned to 

 MicrocebusX. 



In both skeletons there are thirteen dorsal and seven lumbar ver- 

 tebrae ; but neither the axial nor the appendicular skeletons present 

 any noteworthy characters in either specimen. 



The close affinity of the M. mijoxinus of Peters § to M. pusillus 

 being as unquestionable as is their specific distinctness, it is desirable 

 to know if it presents any characters tending to bridge over the gap 

 separating the last-named species from C. milii. 



Now M. myoxinus differs from M. pusillus, besides external cha- 

 racters (as has been pointed out by Dr. Peters ||), in its shorter and 

 less-pointed muzzle, in the greater production forwards of the prae- 

 maxillae, the larger size of the openings in the palate, and also, pos- 

 sibly, in the somewhat longer symphysis of the mandible. More- 

 over the contour of the anterior nares, viewed in profile, is less con- 

 cave, and the palate is less prolonged backwards. Again, the first 

 premolar is quite as extended, vertically, as is the second, instead of 



* Osteographie, Lemur, p. 12. 



t Professor Peters lias been kind enough to send me the exact length of the 

 tarsal bones of his M. myoxin us. 

 I P. Z. S. 1864, p. (Mil 

 I Reise nach Mossambique. p. 14. || Ibid. p. I'J. 



