80 
PROFESSOR OWEN ON THE BELEMN1TE. 
are more nearly approximated towards each other. In reference to the large crystalline 
lens which characterizes the eye in naked Cephalopods, the parts in question can 
only be compared, from their size, with the exterior laminae of the outer division of 
the lens, in which case the larger and denser inner division of the lens has not at all 
been preserved ; which is by no means a probable occurrence, and induces me to 
reject this analogy. If we compare them to the strong external tunic of the eye, 
their outward convexity would lead to their being referred to the cornea. But this 
part, in all existing Cephalopods is a modification of the integument, and continuous 
with it, presenting a less degree of convexity than in the fossils, less thickness, and 
a less definite extent. Viewing, however, the relative position, form and structure of 
the parts under consideration in the two specimens in which they are preserved, the 
most probable conclusion respecting their nature appears to me to be that which 
refers them to the anterior or external tunic of the eye-ball, in which case they indi- 
cate a thicker, stronger, more distinct, more extensive, and more convex cornea in 
the Belemnite than in any known existing Cephalopods. 
Just behind the eves is an oblong body in which a fine longitudinal arrangement 
of fibres is visible; this may be the remains of the funnel: in the adjoining part of 
the mantle the transverse fasciculi are, as in the other specimens, plainly discernible. 
The left fin (e) is well preserved, and the contour of part of the right fin, as it seems 
to me, is traceable, folded back upon the mantle. The left fin presents exactly the 
same relative size and semi-oval contour of the free margin which is shown in Mr. 
Pratt’s specimen; it has been slightly displaced, and advanced obliquely near the 
anterior border of the mantle. A very compact shining dark-coloured substance at 
the detached basal margin of this fin may be the charred remains of its supporting 
cartilage. The right fin, the free border of which is bent inwards upon the mantle, 
as is not unusually seen in ordinary naked Cephalopods, has preserved its true posi- 
tion, rising a little above the visceral chamber of the phragmocone. The most im- 
portant additional fact which we derive from the present specimen is the continuation 
of the mantle over the sheath of the phragmocone, proving indisputably the internal 
position of that part. The chambered division and thin calcareous and nacreous 
structure of the crushed remains of the phragmocone are quite identical with those 
of the phragmocones preserved with the spathose guard in the specimens from Mr. 
Pratt’s and Mr. Broderip’s cabinets. 
In the present specimen about one inch of the apex of the phragmocone has been 
separated from the rest, but its impression is distinctly preserved : in this we may 
trace the longitudinal fold of the crushed capsule, and the impressions of the cham- 
bers and septa to within a few lines of the apex. At the anterior part of the phrag- 
mocone we have the depression in which the ink-bag with its indurated contents was 
lodged. Remains of a thin horny plate are situated anterior to the ink-bag. 
The evidence afforded by the above-described specimens of the paucity in number 
and superiority in size and complication of the cephalic tentacles of the Belemnite,. 
