142 UPPER CRETACEOUS ITELEOSTS 
part is short and inclined antero-ventrally. The opercular process is pronounced 
and in the upper half of the bone. The lateral face of the hyomandibular bears a 
prominent crest running from the anterior head region back to the posterior edge. 
In front of the crest the hyomandibular is thin and tapers ventrally, this region is 
covered laterally by the metapterygoid. 
The quadrate is a stout triangular bone with a transversely arranged condyle. 
Postero-dorsally the upper edge is excavated. This indentation marks the upper 
region of the groove on the medial face of the quadrate which housed the symplectic. 
The symplectic is narrow and inclined forwards ventrally. The posterior edge of 
the quadrate is thickened. Dorsally the quadrate contacts the metapterygoid and 
anteriorly attaches to the postero-medial region of the ectopterygoid. 
The metapterygoid is a flattened membranous bone overlapping the anterior 
extent of the hyomandibular. Laterally on the metapterygoid a shallow crest 
passes obliquely backwards. More dorsally this crest marks the anterior edge of the 
metapterygoid. Anteriorly the metapterygoid contacts the postero-dorsal part of 
the ectopterygoid. 
The ectopterygoid is elongate and bent through a slight angle near to its posterior 
end. Anteriorly the ectopterygoid meets the palatine in an elongate suture. A 
single row of teeth is present on the ectopterygoid, and these are acutely pointed, 
laterally compressed and evenly spaced. The teeth decrease in length towards the 
posterior region, where they are inclined slightly forwards. The teeth are finely 
striated, unexpanded basally and firmly fused to the bone. The tooth row is 
continuous on to the palatine. As well as the marginal row of teeth the palatine 
has an inner row of longer, more needle-like teeth. The palatine is supported 
by the lateral ethmoid dorsally. This latter bone is expanded above the dorso- 
medial surface of the palatine and firmly attached to it. Anteriorly the palatine 
articulates with the lateral edge of the vomer. The palatine has a small dorso- 
lateral maxillary process near its anterior end. This process is excavated terminally, 
and was filled and capped by cartilage in life. 
Dermal upper jaw. The premaxilla is elongate and makes up the anterior half of 
the oral border of the upper jaw. Anteriorly the premaxilla is deepened and 
wrapped around the snout. The lateral face is ornamented with a large number of 
minute tubercles. The premaxilla tapers posteriorly and lies ventral to the maxilla. 
The dorsal edge of the premaxilla is inserted into a shallow groove on the ventro- 
lateral region of the maxilla. A fringe of small pointed teeth is present on the oral 
border of the premaxilla. 
The maxilla is long and thin with an expanded and medially inclined head. The 
facet on the maxilla which housed the maxillary process of the palatine is small and 
bounded fore and aft by small bony projections. A marginal tooth row is con- 
tinuous with that on the premaxilla, but posteriorly the teeth are lengthened and 
inclined forwards. 
Above the posterior end of the maxilla is a conspicuous supramaxilla which 
narrows anteriorly but is deeper posteriorly where it extends beyond the end of the 
maxilla. The supramaxilla is ornamented with minute tubercles. 
