206 UPPER CRETACEOUS TELEOSTS 
The mesethmoid is prominent, extremely well ossified and with its maximum 
width equalling the interorbital width of the frontals. The mesethmoid is blunt 
posteriorly where it contacts the frontals, and is hollowed out internally where it is 
filled with cartilage. Weitzman (1967 : 526) states that Awulopus possesses a 
myodome bone in this region, separate from the ethmoid ossification, also that 
capsular ethmoid bones appear to be fused to the mesethmoid. The lateral pro- 
jection of the mesethmoid inclines ventrally to terminate in an articulatory facet. 
These wings are associated with corresponding, but smaller, projections from the 
vomer and together provide the articulatory facet for the anterior region of the 
palatine. Anteriorly the mesethmoid edge has a small median U-shaped indentation 
which houses a small circular knob of cartilage, presumably the rostral cartilage. 
Arising from the centre of the bone and passing antero-laterally are two smooth 
ridges which extend right to the edge. The anterior edge of the mesethmoid 
between these two ridges provides the articulatory region for the short ascending 
processes of the premaxilla. 
The vomer is attached anteriorly to the ventral surface of the mesethmoid and its 
internal extensions parallel those of the mesethmoid. Dorso-laterally a facet 
between the dorsal surface of the vomer and the ventral surface of the mesethmoid 
contains the articular head of the maxilla. Antero-ventrally the vomer has two 
oval patches of teeth, on either side of the mid-line, each containing seven or eight 
small, acutely pointed, recurved teeth. The anterior end of the palatine lies against 
the lateral vomerine region so that the palatine teeth are continuous with those on 
the vomer. The vomer is produced posteriorly into a short shaft applied to the 
ventral surface of the parasphenoid. 
The parietals are transversely elongated bones meeting in the mid-line, contacting 
the frontals anteriorly, the pterotics laterally and the supraoccipital and epiotics 
posteriorly. The dorsal surface of the parietal, like the frontal, is unornamented 
except for a low transverse wavy ridge extending from the lateral edge almost to the 
mid-line. Laterally, the transverse portion of the supratemporal lies on the dorsal 
surface of the parietal, fitting against the posterior edge of this ridge. More medially 
the supratemporal sensory canal passed across the parietal behind the ridge. The 
supraorbital sensory canal terminates posteriorly on the parietal. 
The supraoccipital appears on both dorsal and posterior faces of the skull. The 
small posteriorly directed supraoccipital crest does not extend above the plane of the 
skull-roof. 
The pterotic forms the postero-lateral region of the neurocranium, meeting the 
sphenotic anteriorly and the frontal and parietal medially in the roof of the post- 
temporal fossa. A slight crest on the pterotic passes postero-laterally. This crest 
contains the otic branch of the infraorbital sensory canal which opens midway along 
the crest, from where it continues in a flanged groove. Postero-medially the supra- 
temporal is closely applied to the pterotic. The extreme posterior end of the 
pterotic is drawn out into a small acute spine which lies ventral to the longitudinal 
limb of the supratemporal. The lateral line canal passed through the supratemporal 
to enter the pterotic posteriorly. The posterior pore in the pterotic for this sensory 
