8 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.61. 



ridge. This broad, deep channel on the squamosal posterior to the 

 glenoid surface is the groove for the external auditory meatus, which 

 continues its course outward by winding around the postglenoid 

 process of that bone. The stout zygomatic process projects laterally 

 and anteriorly to articulate with the jugal and with the postorbital 

 process of the frontal. The petrous portion of the squamosal over- 

 rides the descending lateral wing of the basisphenoid. 



BASISPHBNOID. 



The basisphenoid is a wholly flat bone, probably entirely concealed 

 by the expanded wings of the vomer. By removing a portion of the 

 overlying vomer it was found that the presphenoid is permanently 

 separated from the basisphenoid by an open transverse suture. Two 

 horizontal processes arise from the anterior end of the basisphenoid, 

 one of which is the ala temporalis; the other appears on the sur- 

 face of the temporal fossa as the external pterygoid. The descend- 

 ing lateral wing of the basisphenoid unites with the petrous por- 

 tion of the squamosal to form the anterior margin of the tympano- 

 periotic recess. 



VOMER. 



Since one side of the palate has been destroyed, one is permitted 

 to trace the course of the vomer for most of its extent. The vomer, 

 judging from the exposed surface on the right side of the skull, is 

 more expanded in the rostral region, where the maxillae abut upon 

 it by their rounded margins, than near the palatines, where the 

 former have commenced to conceal it with their marginal plates. 

 The curvature and outlines of a section of the vomer, 14 inches in 

 length from the rostral region, bears out this impression. 



The vomer, which presumably was partially concealed by the pala- 

 tines, again makes its appearance at the point where these bones 

 commence to diverge from one another. It is characterized here by 

 a prominent carina similar to that which separates the palatines in 

 the living Megaptera nodosa^ while posteriorly it gradually dimin- 

 ishes in height toward the base. The loss of the posterior margin 

 of the vomer prevents the determination of the point where the 

 carina disappears. Laterally the vomer is in contact with the vagi- 

 nal processes of the internal pterygoids. 



It is difficult from the present specimen to secure anything like an 

 adequate idea of the shape or relationships of the palatines to the 

 adjoining bones. The skull has been considerably crushed inferiorly 

 in the palatal region, as mentioned previously, and as a result the 

 maxillary-palatine sutures and the true outlines of the palatines are 

 somewhat obliterated. The imperfectly preserved palatine over- 



