62 UPPER CRETACEOUS TELEOSTS 
tapering in height anteriorly. Postero-dorsally it is supported by the ventral region 
of the lateral ethmoid, and more anteriorly it is associated medially with the lateral 
parts of both the mesethmoid and vomer. Anteriorly the palatines continue in 
advance of the mesethmoid and meet in the mid-line, terminating anteriorly in an 
acute point. Traces of teeth are seen along the length of the palatine. 
The dermal upper jaw is composed of two bones, the premaxilla and the maxilla. 
Each bone appears to contribute about half of the oral margin of the upper jaw. 
The premaxillae are produced for a considerable length in advance of the end of the 
palatines, and also meet in the mid-line. The premaxillae lie lateral to the palatines 
and have a smooth external surface. No traces of teeth are visible on the pre- 
maxillae. Only the posterior region of the maxilla is visible, i.e. where it enters the 
gape, and the anterior extent cannot be ascertained. The maxilla is a relatively 
shallow lamina of bone bearing a row of minute teeth. 
The mandible is long and very shallow, and only extended as far as the anterior 
end of the palatines. The articular facet is shallow and ill-defined and there is no 
distinct coronoid process, the rear edge of the articular merely sloping forwards to 
contact the dentary. The dentary is deeply indented posteriorly and this indenta- 
tion is occluded by the forward extent of the articular. A small angular element 
occurs below the articular facet. A lateral flange, running in a longitudinal direction, 
is present on the articular bone; when the jaws are closed the posterior end of the 
maxilla rests on the dorsal surface of this flange. Orally the dentary bears traces of 
teeth. No ornamentation occurs on the lower jaw. 
Opercular bones. The preoperculum is inclined forwards ventrally where it is 
associated with the rear edge of both the hyomandibular and the quadrate. It isa 
narrow bone with a slight ventral expansion. The operculum is very large and is 
as deep as it is long with no ornamentation. The suboperculum is as long as the 
operculum but is considerably shallower and its dorsal region lies medial to the 
ventral region of the operculum. An interoperculum is not present. 
Fins and fin supports. The fins are shown in the reconstruction, Text-figure 28. 
The pectoral girdle is hardly visible in the specimen, only traces of the cleithrum can 
be seen behind the opercular apparatus. The cleithrum is narrow with a consider- 
able vertical and horizontal extent, following the contour of the rear edge of the 
opercular bones. The pectoral fin insertion is high up on the flank, above the mid- 
line of the body. The fin consists of at least 10 branched and segmented rays. 
The pelvic bones are narrow fragile slips of bone positioned below the middle 
of the dorsal fin. The pelvic fin rays are feeble but all are branched and segmented, 
totalling at least 7 in number. 
The dorsal fin is short but relatively deep, the first two or three rays being longer 
than the basal length of the fin. The fin consists of about 6 rays which are relatively 
stout, though flattened, and only appear to be segmented at their extreme distal ends. 
The radial elements supporting the fin rays are short with an expanded articulatory 
region. The first radial also bears a slight anterior expansion. 
The anal fin is composed of at least 8 rays and is remote in position. 
