326 
ACTIXOPTERYGII. 
back ; anal fin much smaller than the dorsal. Scales finely and 
closely tuberculated; the tubercles only rarely fusing into trans¬ 
verse striae on the hinder half of the scale. 
Form. 6f Loc. Lower Lias: Dorsetshire. 
P. 3654. The type specimen, being the head and greater portion of 
trunk, vertically crushed, described and figured by 
Egerton, Joe. eit. 1872 ; Lyme Begis. Both description 
and figure are unsatisfactory. The head is crushed 
obliquely and exposed from below. Bemains of a large 
gular plate appear between the fragments of the smooth 
mandibular rami, and there are clusters of the small 
slender teeth. The premaxilla cannot be identified with 
certainty, and there is no evidence as to how the teeth were 
disposed ; one narrow fragment of bone shows the bases 
of three series of teeth. On one large expanded bone, 
which may be entopterygoid, the teeth cover an extensive 
area and are in part merely fine granulations. The 
hyomandibular is well shown on one side, but in the 
published drawing it is not distinguished from an adjoin¬ 
ing element which appears to be the displaced meta¬ 
pterygoid. The process of the hyomandibular for the 
support of the operculum is long, but its hinder end is 
connected with the upper and lower extremities of the 
element by a thin lamina of bone. Behind the hyoman¬ 
dibular, parts of the operculum and suboperculum are 
seen from within. The vertebral centra are not “ com¬ 
pletely ossified,” but are represented merely by distinct 
hypocentra and pleurocentra; their arches are obscurely 
indicated through the displaced squamation. The 
tubercles on the scales are occasionally elongated, and on 
the hinder portion of some of the flank-scales they are 
observed to pass into transverse strife which terminate in 
feeble denticulations. The fins are too fragmentary for 
detailed description. Enniskillen Coll. 
P. 876 x. Fragmentary remains of head, pectoral fins, and anterior 
scales ; Lyme Begis. Part of the smooth outer face of 
the left dentary, with its coronoid elevation, is shown ; 
and there are scattered examples of the characteristic 
slender teeth. The cranial roof is imperfectly exposed 
from within, and there are remains of the hyomandibular, 
supposed entopterygoid, and numerous other elements. 
The operculum, though fragmentary, is clearly deeper 
