I40 MAURICE G. MEHL 



portion of them is to be seen on the general plane of the palate 

 surface. They seem to form the posterior half of the inner boun- 

 daries of the posterior palatine openings. Near the anterior limit 

 of the basisphenoid they bend abruptly upward from the roof of 

 the broadly rounded palate arch and extend above the parasphe- 

 noid. Anteriorly they approach each other till they embrace the 

 para- and presphenoid and, still farther forward, close together below 

 them.. They meet the transverse bones broadly at the posterior 

 ends of the posterior palatine foramina, the suture being directed 

 backward from this point and a little inward. Posteriorly they 

 close with ample and firm contact on the basi-pterygoid process. 

 From this union the pterygoids send back and outward narrow 

 processes which meet like processes of the quadrates about midway 

 between the quadrates proper and the pterygo-sphenoid union. 

 Their relations with the various elements seen in a posterior view 

 will be discussed below. 



The transverse hones, seen from below, present an approximately 

 triangular outline. They form the lateral borders of the posterior 

 palatine foramina and the anterior borders of the post-temporal 

 vacuities. The broad pterygo-transverse sutures run back and 

 inward from the posterior ends of the posterior palatine openings 

 toward the bd,si-pterygoid process. Along the outer anterior side 

 the transverse bones unite with the maxillae for a distance of about 

 40 mm. and at a somewhat less distance with the jugals. The 

 postero-lateral corners are bent downward along a line running 

 from their inner posterior angles obliquely outward from the di- 

 rection of the posterior palatine openings and extend some 14 mm. 

 below the general ventral plane of the skull. 



The ventral surface of the parasphenoid is exposed the entire 

 length of the inter-pterygoid vacuity and both the para- and the 

 presphenoid are free from the matrix for some distance along one 

 side. Their union is clearly indicated by a shallow longitudinal 

 groove. At their union with the basisphenoid they form a thin, 

 vertical plate which gradually thickens anteriorly very slightly and 

 becomes rounded below. They are visible from below for a dis- 

 tance of 95 mm. Anteriorly at this distance, about 42 mm. back 

 of the posterior border of the nares, the pterygoids meet below these 



