age 



PLATE XI IT. 



Fig. P; 



1. Metriorhynclnis durobrivense, Lydekker, sp. ; skull of a young 



individual, from above: one-half nat. size. [R. 2618.] 199 



2. Ditto; prefrontal-lachrymal region of skull, from below: one-half nat. 



size. [R. 2618.] 148 



3. Ditto; posterior surface of skull : one-half nat. size. [R. 2618.] 155 

 4, 4 a. Ditto; vomer (parasphenoid) from above (4) and below (4 a) 153 



5. Ditto ; tooth, from outer side : nat. size. [R. 2039, ! 153 



a., anterior end. 

 ah., alisphenoid. 

 loc, basioccipital. 

 car. <J- X?, foramen for the carotid artery and 

 (?) vagus nerve. 

 d.c/., dorsal groove of vomer (parasphenoid). 

 eu.m., median eustachian opening. 

 c.r.o., exoeeipital. 



for., foramen between parietal and supra- 

 occipital. 

 jr., frontal. 

 j-, jugal. 

 j.f., facet on lachrymal for union with jugal. 

 ?., lachrymal. 

 m.p., median plate of vomer (parasphenoid). 

 vi.v., maxilla. 

 »., nasal. 



Mi-., external nave*. 

 p., posterior end. 

 pal.f., facets for union with the palatine. 

 par., parietal. 

 pm.v., premaxilla. 

 po.f., postfrontal. 

 pr.f., prefrontal. 

 ■pr.o., prootic. 

 q., quadrate. 

 q.j., quadrato-jugal. 

 soc, supraoccipital. 

 s.pal., surface for palatine. 



sq., squamosal. 

 VII., foramen for the seventh (facial) nerve. 

 XII., ., ., „ twelfth (hypoglossal) 



nerve. 



