148 UPPER CRETACEOUS TELEOSTS 
Hemisaurida hakelensis sp. nov. 
(Text-figs. 67-69) 
Diacnosis. Hemisaurida of standard length up to 5-5 cm. Length of the head 
with the opercular apparatus two and a half times the maximum depth of the head, 
and equal to just under half the length from the pectoral arch to the base of the 
caudal fin. Vertebrae 35 in number of which 17 are caudal. Dorsal fin in the 
second quarter of the back with 11 rays. Anal fin remote and consisting of 9 rays. 
Horotyre. B.M.N.H. number P.48777, a flattened fish from the Middle Ceno- 
manian, Hakel, Lebanon. 
MATERIAL. The holotype and specimen numbers P.48778, P.48779, P.48780 in 
the B.M.N.H., from the Middle Cenomanian of Hakel, Lebanon. 
DESCRIPTION. Neurocranium. The neurocranium is somewhat elongate, shallow 
and with a large orbital region. The orbit is bordered dorsally by the frontal and 
limited anteriorly by a prominent lateral ethmoid. At the hind end of the orbit, the 
frontal extends laterally above the sphenotic. The sphenotic passes ventro- 
medially to contact the prootic within the anterior portion of the hyomandibular 
facet. The prootic forms part of the lateral wall of the cranial cavity and both the 
anterior and posterior openings of the trigemino-facialis chamber can be seen in it. 
The openings are separated by a strut of the prootic. Ventrally the prootic contacts 
the ascending process of the parasphenoid. At the base of the ascending process is 
a notch in the anterior edge marking the passage of the efferent pseudobranchial 
artery. Posterior to this notch, still in the parasphenoid, is a forwardly directed 
foramen which transmitted the internal carotid artery. The parasphenoid, in the 
base of the orbit, bears lateral flanges. 
Hyopalatine bones. The hyomandibular is a shallow bone with an elongated head. 
The anterior region of the head fits into the cup-shaped facet formed from the 
sphenotic and prootic, whilst the posterior region fits into an elongated facet 
within the pterotic. A prominent lateral crest, from the anterior head region, 
passes postero-ventrally to the rear edge of the hyomandibular in the vicinity of 
the opercular process. The crest passes ventrally along the rear edge of the bone 
and disappears at the ventral extremity. A second crest passes ventrally from 
the posterior head region of the hyomandibular to contact the main crest where 
the latter meets the posterior edge of the bone. The hyomandibular curves strongly 
forwards ventrally (Text-fig. 67). The anterior part of the hyomandibular is thin 
and laminate and overlapped by the prominent metapterygoid. This latter bone 
supports an oblique crest and is relatively large, with rounded posterior and dorsal 
edges. The ventral edge is straighter and contacts the dorsal edge of the quadrate. 
The quadrate is large and triangular with a prominent condyle. The rear edge of the 
quadrate forms a continuation of the forward curvature of the ventral hyomandi- 
bular region. The quadrate condyle thus lies beneath the rear end of the orbit. 
The ectopterygoid and the palatine form a continuous strut of bone ascending 
gradually from the quadrate. The suture between the two bones is below the 
extreme anterior orbital region. The endopterygoid is thin and attached to the 
