882 



MR. R. W. PALMER ON THE 



the lower surface of the periotic exposed. The secondary palate 

 is completely lost. 



In a longitudinal section of the skull (text-fig. 154) the great 

 thickness of the bones and the general development of diploe are 

 striking features. A skull which supported such massive tem- 

 poral muscles as this beast possessed had of necessity to be of a 

 strong build. The extreme shallowness of the pituitary fossa and 

 the practical absence of clinoid processes are features of interest, 

 while the mode of attachment of the cribriform mass to a groove 

 in the pre-sphenoid is curious. The pear-shaped cerebral fossa is 

 partly separated from the cerebellar by the heavy tentorial ridge, 



Text-fisf. 154. 



Median section of skull of Anoplotherivm. 



Lettering as in preceding figures, with addition of h.s., basisphenoid ; cr.p., cribri- 

 form plate ; f.fo., floccular fossa ; v.d., canal for vessel of diploe. 



most of Avhich belongs to the squamosal. The sjiacious cavity for 

 the transverse s'nus opens immediately behind this ridge above 

 the periotic. It goes straight down to the post-glenoid foramen 

 and is joined by a canal for a vein which ran in a deep groove on 

 the side-wall of the skull, and was formed by the confluence of 

 two vessels which ran in the substance of the alisphenoid. 



The main features of the individual bones of the skull will now 

 be outlined. 



The bones of the occipital segment are indistinguishably fused 

 together, but their anterior sutures are for the most part distinct. 

 The thick supraoccipital is of great extent owing to the extreme 

 development of the lambdoid crest, of which it forms the entire 



