Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 605 
rays as the pectorals ; the exact number is, however, not determinable. The fins 
are 1-0 inch in length, and the constitution of the fin-rays is similar to those of the 
pectoral fins. 
The scales are not well preserved on most of the specimens; they were thin 
and comparatively small in size. There is no evidence of the large dorsal plates 
characteristic of the genus Eurypholis; neither is there any evidence of the lateral 
rows of plates extending on each side of the body from the head to the tail, as 
in that genus. 
The relationship of this species has already been referred to under its generic 
appellation. 
Formation and Locality —Upper Cretaceous: Sahel Alma, Mount Lebanon. 
Ex coll—Lewis Collection ; R. Damon, Esq., Weymouth. 
Genus. Phylactocephalus.* Davis. 
Body elongated, oval, robust; head large, protected by thickly enamelled 
plates; mouth large; jaws strong, and provided with numerous small, conical, 
acutely-pointed teeth. Spinal column strong; vertebrze not numerous; ribs many, 
and fine. Dorsal fin near the head; anal close to the caudal, which is deeply 
bifurcate ; pectoral fins attached to the side of the body; ventrals abdominal. 
Seales very small, free posterior margin pointed. 
This genus, whilst possessing many peculiar characters, appears to be most 
nearly related to Eurypholis and Eurygnathus. The very strongly plated head 
and jaws, the latter provided with numerous sharp teeth, associate it with these 
genera; but the absence of the long teeth, which characterize these genera, will 
readily distinguish this one. The arrangement of the fins is similar to Kurypholis 
so far as the paired fins are concerned ; but the dorsal of Phylactocephalus is nearer 
the head and the anal is nearer the tail. In Eurygnathus the dorsal fin is remote, 
whilst the anal occupies a similar position to that of the genus now described. It 
is separated from Ischyrocephalus, V. der Marck, by the absence of the long 
anterior teeth characteristic of that genus. 
Phylactocephalus microlepis, Davis. 
(Ply xxxy., fig: 2:) 
This specimen, which serves as the type of this species, is unique, and possesses 
several peculiar features which dissociate it from all its piscine congeners of 
the chalk of Lebanon. It possesses a strong osseous framework; its head is 
PvrAdKos, a guard; Kepadn, head. 
TRANS, ROY. DUB, SO0., N.S. VOL. Il 4N 
