534 DE. c. J. roKSTTH MAJOU ON A LEMUEOiD SEULL. [June 20, 



margins of the right and left external auditory meatus across the 

 upper surface of the skull. In the fossil this part of the superior 

 outline of the skull is nearly horizontal, so that the anterior portion 

 of the interparietal appears almost on the same level with the 

 highest region of the parietals. The flattened posterior moiety of 

 the interparietal slopes suddenly down to the occipital crest ; the 

 occiput proper is almost vertically truncated, much as in the skull of 

 Mycetes. On the other hand, in Hapalemur, as in existing Lemuroids 



■Fig. 2. 





Skull of fossil Leinuroid. Side view, two-thirds nat. size. 



generally, the occipital crest has a more oblique direction, its 

 inferior edge being considerably more in advance of the upper one ; 

 and the whole occiput partakes partly of this same direction. 



The inferior margin of the postorbital frontal processes is 

 cuttingly sharp in the Malagasy fossil ; this is also characteristic 

 of Hapalemur (both H. simus and H. (friseus). In the former the 

 frontals extend laterally somewhat farther backwards than in 

 the latter ; and the postero-superior margins of the postorbital 

 processes continue backwards in the shape of two sharp crests, 

 which unite at the coronal suture. No sagittal crest is visible on 

 the median line of the parietals, which are as yet separated ; but 

 it appears obvious that this Avould be the case in a more aged 

 specimen. In Hapalemur, even in adult specimens, no such 

 elevated frontal crests are developed, and instead of a sagittal 

 crest there are two temporal ridges remaining low and separated 

 anteriorly, although near the interparietal they converge to form 

 a feeble median crest. 



The interorbital region is absolutely broader in Ilapal. simus, and 

 is, besides, vaulted from before backwards and from right to left, 

 owing to underlying frontal sinuses. These last are not entirely 

 absent in the fossil, as seen in the inferior broken portion ; they 

 extend even partly into the postorbital processes. 



The olfactory fossa appears very large in the fossil, as is the 

 case in Lemuroids generally. The anterior end of the cribriform 

 plate is but slightly more elevated than the posterior ; this is the 



