the Sh-uU of Di:uloinu.l)ii. 307 



inwards which is Ijouudcd by the maxilla, transverse bone, 

 and very !>li;:htly l)y tlie pti-ryj^oid in a ventral view, but is 

 lar-icly ei)vercd by the pteryi^oid (h)r^ally (lij^. 3). 



How much of the postorbital bar is formed by the jugal 

 is uncertain. 



Ectopteniyoid. — The transverse bone is a very small 

 L-shaiK'd bone, luiiled by a rather loose suture with the 

 pterygoid, bounded laterally by the jugal and anteriorly by 

 a short contact with the maxilla and a rather longer one 

 ■with the palatine. 



Its inner border at tlie corner of the L forms the outer 

 and j)osterior edges of the very small suborbital foramen ; 

 the rest of the lower limb of the bone is joined by the 

 palatine. 



The bone appears to be completely overlaid dorsally by 

 the pterygoid. 



Palatine. — The palatines arc widely separated from one 

 another by the vomer (fig. 3). Each may be described 

 as consisting of tsvo j)arts, the main body of the bone and 

 the secondary plate. The body of the bone is an almost 

 vertically placed plate of bone united below to the vomer and 

 forming the side wall of the great canal of the posterior 

 nares. The postero-lateral corner of this jilate is reflected 

 ui)wards so as to be nearly horizontal in position, and unites 

 with the pterygoid and transverse bone. The lower border 

 of this bone stands up as a ridge lying parallel to and just 

 within the teeth ; it is continuous with the posterior border 

 of the secondary plate of the palatine. The secondary 

 plates of the ])alatines form to<:ether the floor of the narial 

 ))assage, and their posterior borders meet at a circular angle 

 of about 100°. 



The scondary plate bears a patch of very small irregular 

 granules which appear to have enamelled tips; these lie near 

 the middle line and towards the back. There seems to be 

 little doubt that these granules are homologous with the 

 palatal teeth described by Seeley in Cynorjnathus. The 

 secondary plates of the palatines unite in front with the 

 similar plates of the maxilUe, but I cannot be certain of the 

 sutures. 



Maxilla.— '\\\c maxillse are broken off anteriorly, but their 

 posterior relations are well shown. Each consists of a 

 massive alveolar part which receives the roots of the molar 



