414 



HAKRIS HAWTIIORXE WILDER ON 



fero- later*' 



Process 



P»-OC.M 



Between them is a flattened depression, the internasal fossa, which lodges the internasal 

 plate of the chondrocranium. The dorsal side possesses few features of interest. At the 

 anterior end is a longitudinal groove in which rests the ascending process of the premaxil- 

 lary and farther back is an obhque temporal ridge, extending from the olfactory notch to 

 the middle of the interfrontal suture, and servdng as the anterior limit of the temporalis 

 muscle. 



2. PARIETAL. This is the most irregular bone of the skull, and tlic largest, with the 

 exception of the parabasal. It possesses extensions in several directions, but it is so irreg- 

 ular that the numljer 

 of definite pi'ocesses, 

 of which Wiedersheim 

 enumerates five, is 

 somewhat arbitrary. 

 Of these, the most 

 important function- 

 ally as well as ana- 

 tomically, is the lon- 

 gitudinal ridge upon 

 the ventral side, the 

 edge of which comes 

 in contact with the 

 parabasal, and which 

 functionally replaces 

 an orbito-sphenoid and 

 serves as the side 

 of the brain case. 

 This may be called 

 the orlji to-sphenoid 



PrectfSS- 



» PS. 



QunArttte 

 Pfttiri 



pro -otic 



Ptrocess. 



Opirrtofic 



i'ig. 11. Twii views of rii;ht parietal. 

 ave de.sigiiated by an x. 



Pro- otic 

 Process 



DORSAL 





X 3. Coiilaet surface.s witli otlier bones 



process, as 



sugges- 



tive of its function, 

 and this process together with the uncinate process on the frontals completes the U- 

 shaped ridge mentioned aliove. This ridge is perforated by several very slanting foramina 

 for the transmission of the nerves of the eye muscles, but the exact identification of these 

 must be left for later investigation. The irregularly curved and very thin dorsal surface 

 may be conveniently divided into a nearly flat anterior portion and a decidedly convex 

 posterior portion, taking its shape from the otic capsule which it covers. From the 

 anterior portion proceed three processes, an antero-median, an antero-lateral, and a quad- 



