134 UPPER CRETACEOUS TELEOSTS 
compression. Fine longitudinal striations are present on the teeth and on the 
expanded bases. The second type of teeth on the ectopterygoid are minute and 
collected into a patch posteriorly. The ectopterygoid meets the palatine anteriorly 
in an elongated suture, extending forwards alongside the palatine. 
The endopterygoid is thin and membranous, meeting the metapterygoid poster- 
iorly. The ventral surface of the endopterygoid is convex and supports a large oval 
tooth-patch. 
The palatine is prominent and bears three rows of large teeth, identical in form to 
those on the ectopterygoid. Posteriorly the palatine tapers to fit between the 
ectopterygoid and endopterygoid. At the posterior end the teeth on the palatine 
are reduced to a single row. The tooth row on the ectopterygoid is continuous with 
the most lateral tooth row on the palatine. In this outer tooth row the teeth 
decrease in size anteriorly and posteriorly. The central row of teeth are smaller 
and more irregular both in size and position. The innermost tooth row extends the 
entire length of the palatine and has the largest teeth in the upper jaw. The dorsal 
surface of the palatine is longitudinally grooved for the reception of the ventral 
expansions of the lateral ethmoid. Anteriorly the palatine is associated with the 
lateral edge of the vomer. 
Dermal upper jaw. The dermal upper jaw is shown in lateral view in Text-figure 
61. The premaxilla is elongate and forms the majority of the oral border. The 
anterior region is expanded where it wraps around the front end of the snout to 
contact its partner of the other side. This expanded region is ornamented with 
numerous, evenly spaced, minute tubercles. Posteriorly the premaxilla is long and 
h.mx 
Fic. 61. Halec eupterygius (Dixon). Restoration of the skull in lateral view. 
