166 UPPER CRETACEOUS TELEOSTS 
suture. Although thin the pelvic bones are thickened somewhat posteriorly to form 
an articulatory condyle. A crest passes anteriorly along the lateral edge of the bone. 
The main body of the bone lies horizontally whereas the condyle is inclined obliquely. 
Medial to the condyle, the ventral postcleithrum is firmly attached. The anterior 
ends of the pelvic bones lie between the anterior coracoid processes. 
The pelvic fin is long, prominent and composed of 8 rays. All the rays are seg- 
mented distally, and except for the first one or two are branched. The fin has a 
basal, asymmetrical, pelvic splint bone. 
Vertebral column. The vertebral column is shown in the restoration, Text-figure 
76. It consists of 30 vertebrae, of which 17 are caudal. The centra are longer 
than deep, and mesially constricted. The neural arches are relatively stout but 
the spines are delicate. Each neural arch is confined to the anterior half of the 
corresponding centrum. The neural arches on the precaudal vertebrae are only 
loosely connected to the centra, but caudally the contact is much closer. Transverse 
processes only become evident on the posteriormost two or three precaudal vertebrae, 
and the pleural ribs on the remaining vertebrae articulate directly with the centra. 
Several of the most anterior precaudal vertebrae do not appear to possess pleural 
ribs. On the first caudal vertebra the haemal arch is not drawn out into a haemal 
spine, but on all the subsequent caudal vertebrae haemal spines are present. Zyga- 
pophyses are in evidence on the ventral regions of both precaudal and caudal 
vertebrae, whereas on the dorsal region of the vertebral column the zygapophyses 
are non-existent. Epineurals and epipleurals are present on the first 22 vertebrae. 
Median fins and tail. The median fins are shown in the restoration, Text-figure 
76. The dorsal fin is prominent and occurs in the second quarter of the back, 
consisting of 13 or 14 rays. The fifth ray is the longest and all the subsequent rays 
are segmented. The first four rays decrease in size anteriorly. The third and 
fourth rays are unbranched but segmented, but the first and second rays are neither 
branched nor segmented. The radials are long and narrow and unexpanded. The 
medial radials are visible between the bases of adjacent fin rays, as elongate con- 
stricted cylinders of bone inclined obliquely. In the region between the origin of 
the dorsal fin and the occiput three flattened accessory radials occur. The most 
anterior one is associated with the expanded neural spine of the first vertebra. 
The anal fin is composed of Io rays and arises just behind the rear of the dorsal fin. 
The third ray is the longest. It is greatly extended and both segmented and distally 
branched. The subsequent rays are all branched and decrease in size posteriorly. 
The second ray is shorter and segmented, the first is the shortest and spinous in form. 
The caudal skeleton (Text-fig. 77) is composed of several vertebrae. Four 
preural vertebrae are present as separate units, the neural and haemal spines of 
these supporting the accessory rays of the caudal fin. The first preural vertebra is 
fused with the first ural vertebra. A free second ural vertebra is present as a small 
terminal half-centrum posteriorly. The haemal spines of the preural vertebrae are 
elongate, that of preural centrum 2 (the first free preural vertebra) is slightly 
flattened and expanded. The fused preural and ural vertebrae support the par- 
hypural (the haemal spine of the first preural vertebra) and two hypurals. Postero- 
