TUE CIIONDUOCUAXIUJI OF LEriDOSTKUS. 265 



rather than to the pterotic portion of the spheno-pterotic ridge. 

 Tlie I'elations of the processus zygomaticus of ]\'[aii to the region 

 of the roof of the fovea epitympauica — that is to the sphenotic 

 ridge — would tlierefore seem to indicate that it has been derived 

 from, or at least contains, the long, anteriorly projecting process 

 of the postfronto-sphenotic of Poh/jjierus ; and the temporal 

 fossa of Man would arise if that part of the frontal of Pohjpterus 

 that roofs the supraorbital fontanelle were to be suppressed by 

 the wearing action of the musculus temporalis. That angle of 

 the frontal of Pohjpterus that gives ai'ticulation to the post- 

 orbital bone would then correspond to the external angular 

 process of the frontal of Man, and the postorbital bone would 

 correspond to the malar bone of Man ; this all being in accord 

 with my conclusion (Allis, '00) that the maxillary bone of 

 Polypterus is the homologue of the maxillaiy part of the superior 

 maxillary bone of Man, and that neither of these bones is the 

 homologue of the teleostean maxillary. 



Palais de Caviioles, Meiitoii, Fvaiice, 

 April 30, 1919. 



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