36 
ACTINOPTEETGII. 
relatively narrow, their extent not exceeding one quarter the length 
of the skull; orbit very large, its width considerably greater than 
one third the length of the skull; teeth of premaxilla relatively 
long and slender, larger than those both of the maxilla and dentary. 
Opercular apparatus relatively narrow, its width not exceeding one 
third the length of the skull. Radiating lines on anterior scales 
few and indistinct. 
Form. Log. Turonian : Sussex. 
49826. Type specimen, shown of the natural size from the left 
side in PI. VII. fig. 4; Lower Chalk, Lewes. The head 
is imperfect and a fracture crosses the rostral region 
causing some displacement; but the general proportions 
seem to be determinable with sufficient accuracy. The 
posterior suborbital plates {s.o.) are exhibited only 
in an impression of their inner face, and it is uncertain 
how they were subdivided; the transverse fractures may 
or may not represent sutures. There is one long infra¬ 
orbital (i.o.) beneath the eye, and in the orbit itself 
there is a trace of an ossified sclerotic (scl.). The long, 
slender maxilla imperfect at each end, has a very 
slightly sinuous oral border bearing small spaced teeth. 
The premaxilla (j)mx.), with a regular series of larger 
and more slender teeth, is about one quarter as much 
extended as the maxilla. The mandible is imperfectly 
displayed, but the anterior end of the dentary (d.) bears 
slender teeth intermediate in size between those of the 
premaxilla and maxilla. The lower end of the pre¬ 
operculum {p.op.) seems to be completely preserved, 
but is not much expanded and does not exhibit any 
radiating ridges. The operculum fop.) is very imperfectly 
shown, chiefly as an impression, but must have been 
nearly twice as deep as broad. The suboperculum {s.op.) 
is shown to have been smooth, with feeble traces of 
radiating lines, and its width is about as great as its depth. 
The slender clavicle (cl.) is partially exposed, while the 
post-temporal {p.t.) and postclavicular plates {p.cl.) are 
conspicuous. A few of the anterior scales are also pre¬ 
served, the relatively small exposed area marked with 
delicate radiating depressions. Capron Coll. 
