160 MR. ST. GEORGE MIVART ON MICRORHYNCHUS. [Mar. 13, 



les memes particularites ; seulement le canal lacrymal est moiiis 

 avance daus la face et presque marginal ; les orbites sont plus 

 grandes, l'incisif est encore plus petit, et la machoire infe'rieure a 

 son angle plus large, plus arrondi, et sa symphyse plus lougue et 

 plus oblique." 



Front view of skull. Scale, nat. size. 



One of the most striking characters of the skull of M. laniger is 

 the exceeding shortness of its facial part, which distinguishes it from 

 all other Lemuroidea, with the exception perhaps of Tarsius and 

 Cheiromys. As in Tarsius and some Galagos, the antero-posterior 

 extent of the anterior opening of the orbit greatly exceeds the length 

 of the muzzle in front of it. 



When viewed from above, the entire skull is seen to be broadest 

 between the outer margins of the orbits ; but the greatest width of 

 the cranium proper is in a line drawn just behind the posterior ends 

 of the zygomatic arches. As in Indris the mastoidal region of the 

 periotic is not inflated, but there is a prominence at, and above, the 

 posterior root of each zygoma just above the aperture of the external 

 auditory meatus. This peculiar enlargement is absent in Indris and 

 in all the other genera of Lemuroidea ; but when compared with 

 some of the smaller species of the suborder (as the Nycticebince and 

 Galagonina) it seems to answer to their mastoidal swelling, only 

 placed further forwards. 



The surface of the cranium presents a strongly marked depression 

 (concave both antero-posteriorly and transversely) between the orbits ; 

 behind this the roof of the skull is smoothly and evenly convex, ex- 

 cept a slight concavity just in front of the most anterior point of the 

 supraoccipital. 



There appears to be no interparietal. The two temporal ridges 

 are slightly but distinctly marked. As in Indris, they do not unite 

 to form a sagittal ridge, which is the case in Hapalemur, and some- 

 times in Galago. 



The nasals are rather strongly convex, and are broader at each end 

 than in the middle, instead of narrowing gradually upwards as in 

 Indris. They are shut out from the lachrymal by a narrow process 

 of the maxilla which ascends to join the frontal, the short fronto- 



