152 



DK. H. F. STANDING ON SUBFOSSIL 



Archceolemur there is a very considerable downward extension of the lacrymal in a 

 manner very analogous to the condition seen in certain American forms (text-fig. 48). 

 Dr. Forsyth Major has in this connexion made a laborious comparison of many 

 hundreds of skulls of Lemurs and Monkeys, and even before the discovery of the new 

 forms described in this memoir had already come to the conclusion that neither this 

 character nor the position of the lacrymal foramen can be used as differentiating 



Text-fiar. 48. 



f A 



r^' 



, ^ 



-/ 





Showing shape and extension of lacrymal bone within the orbit and position of lacrymal foramen in various 

 Lemurs and Monkeys : — 1. Young Palceopropithecus ; 2. Arclwolemur edwardsi ; 3. Mesoprointheciis 

 pitJiecoides ; 4. Mycetes palliatus ; 5. Callithrix personata : 6. PropifJiecus edwardsi. 



characters (see text-fig. 48 *). Forsyth Major has also shown that even in the extant 

 Indrisinse the ethmoid enters to a small extent into the orbital wall, while some non- 

 Malagasy genera have a large os planum. There is no doubt that the large size of 

 the orbits of many Lemurs is a character due entirely to their nocturnal habits. 

 This feature is absent in some of our fossils, but appears in some of the Lemur-like 

 South-American nocturnal Monkeys (text-fig. 49). 



Temporal Eegion. — The high, strong zygomatic arch of the majority of the fossil 

 Malagasy Lemuroids has certainly no close analogy with the ordinary condition of 

 this region among the Apes. Is it not probable, however, that this feature is in 

 relation with the heavy jaws, stout temporal muscles, and vertical occiput which have 

 been referred to above 1 In the higher Apes the expanding of the cranial vault and 

 shortening of the region between the foramen magnum and the posterior margin of 

 the palate has brought about a corresponding shortening of the zygomatic arch. 



* Nos. 4, 5, 6 are taken from the illustrations to the study by Dr. Forsyth Major above alluded to. 



