PRIMATES FEOM MADAGASCAR. 



81 



has the same contour as that observable in recent Lemurs, but instead of being inflated 

 and globular in form it has actually a smooth concave surface. The disappearance of 

 the bullae is associated with several minor changes, to which reference may be briefly 

 made. The outer pterygoid laminse of the alisphenoids are widely everted and sharply 

 truncated at their posterior border, the flat plate or bony bridge which in Propitheeus 

 or Indris connects this bone with the auditory bulla being, of course, entirely absent. 



Text-fig. 12. 





Inclination of lower incisors of (A) Palceopropillucus maximus and (B) PitJiecia nifivenUr compared. 

 In disposition the latter bear more resemblance to tbe usual Indrisine type. (See also 

 text-figs. 18 and 22.) 



Test-fiff. 13. 



Restoration of cranium and mandible of Palceopropithecus maximus. X g. 



The flattening down of the suture between the alisphenoid and the tympanic leaves 

 the foramen lacerum medius widely exposed, and the orifice of the Eustachian duct, 

 foramen rotundim, and foramen ovale are all crowded together at the posterior end of 

 this opening. On tracing the Eustachian duct outwards and backwards towards the 

 auditory meatus it is found to open into a narrow chamber greatly flattened in a 



