208 
ACTIXOPTERYGII. 
of preoperculum short and stout; postclavicular plate triangular, 
somewhat longer than deep, and its postero-superior margin ex¬ 
cavated. Pectoral fin arising just above the postclavicular plate, 
the large pelvic fin immediately behind this plate and in advance of 
the origin of the dorsal fin ; dorsal fin somewhat deeper than long, 
comprising 12 rays, and the distance between its hinder end and 
the caudal fin slightly exceeding that between its origin and the 
occiput; anal fin smaller than the dorsal, at least as long as deep, 
comprising 13 rays, and arising much nearer to the caudal than to 
the pelvic fius. Three large dorsal plates behind the occiput, ovate 
in form, very slightly overlapping, ornamented with closely- 
arranged concentric rows of tubercles, and not quite reaching the 
dorsal fin; lateral scutes much smaller, irregularly triangular and 
deeper than broad, perforated by the sensory canal. 
Form. Log. Upper Cretaceous : Hakel, Mount Lebanon, Syria. 
49478 . A vertically crushed specimen, displaying the head and 
opercular bones as shown in PI. XI. fig. 7. The cranial 
roof is shown partly from within, partly in impression of 
the outer ornamented face ; but it merely exhibits the 
large extent of the frontals (/r.), not distinctly indicating 
the other elements. The extended premaxilla 
deepened in front and tapering behind, is conspicuous on 
each side and exhibits the single series of small slender 
teeth, fixed on tumid bases. On the left side the slender 
maxilla (ma’.), with small teeth in its hinder portion, also 
seems to be partly preserved. The orbit (o.) is bounded 
behind by a chain of small, tuberculated circumorbital 
plates (co.), of which four are preservedwhile the whole 
of the cheek between these and the preoperculum is 
covered by posterior suborbitals (s.o.), of which the limits 
are not clear. Both mandibular rami are exposed from 
•within and exhibit the characteristic teeth on tumid bases, 
while that of the right side shows two irregular promi¬ 
nences of bone at the tapering symphysis. Each ramus 
gradually deepens behind and seems to consist of two 
elements, dentary (d.') and articulo-angular (ug.), of which 
the limits are indicated by the impression of the tubercu¬ 
lated outer face of the leftside. The preoperculum {p.op.) 
' is a thickened vertical rod, almost reaching the cranial 
roof above, and terminated below by the short and stout 
posteriorly-directed spine ; a narrow tuberculated lamina 
extends along its posterior margin. The triangular opei- 
