170 
ACTINOPTERTGII. 
numerous delicate intermuscular bones, so that the non- 
appearance of the characteristic short transverse processes 
is perhaps to be explained by the imperfections in the 
mode of preservation. The neural arches and spines are 
very slender, and inclined sharpl}- backwards throughout 
the length of trunk preserved; the delicate ribs seem to 
have completely encircled the abdominal cavity. Traces 
of the contents of the intestine are observed throughout 
the greater part of the abdominal region, extending behind 
the pelvic fins nearly as far as the specimen is preserved. 
One pectoral fin is bent upwards and the other down¬ 
wards, and they are sufficiently well exhibited to indicate 
that they are comparatively large and robust, each with 
about 10 rays. The pelvic fins (plv.) are very remote, 
and observed to be supported b}’ a pair of slender bones 
which are pointed in front. The pelvic fin-rays are much 
more slender than those of the pectoral fins, and perhaps 
about two thirds as long as th-e latter. The fish is broken 
away shortly behind the pelvic fins, and neither side of 
the fossil exhibits the additional fragment represented by 
Davis. Still further back on the left-hand slab, there 
occurs the terminal portion of a tail with a small differ¬ 
entiated caudal fin; but it is very uncertain whether this 
belongs to the fish now described. The dorsal fin-supports 
are well shown as indicated in the drawing, each with a 
small triangular expansion at its distal end; but there 
are no traces of fin-ravs in connection with them. There 
V 
are no undoubted remains of scales. Lewis Coll. 
49542, P. 9169. Imperfect head and greater part of ahdominal 
region, exhibiting a small fish swallowed tail foremost, in 
counterpart. The front half of the right side of the fossil 
is shown of the natural size in PI. XY. fig. 2. The 
cranium in side-view appears less deepened than in the 
existing jS^otacantJius, but it has the same delicate para- 
sphenoid bone. The maxilla, shown on the left side 
of the fossil, is gently curved and comparatively stout, 
but its hinder end is obscured. The mandible is still 
stouter, its articulation below the middle of the orbit, 
its hinder half very much deepened, its short oral margin 
still bearing three slender recurved teeth. The opercular 
apparatus is imperfect and distorted, but below it there 
are distinct remains of about ten delicate branchiostegal 
rays. The constricted veitebral centra are fractured, 
