74 
PROFESSOR OWEN ON THE BELEMNITE. 
A little above the capsule of the phragmocone, on the left side, there is a flattened 
transversely fibrous body (e) with a rounded external border, so well defined as to 
excite the suspicion that it must have belonged to some part superadded to the 
muscular mantle; its nature is demonstrated in the specimen next to be described. 
An oblong portion of the same fibrous and muscular tissue as the mantle, lying 
obliquely in front of the anterior margin of the mantle, and in which both a longi- 
tudinal and transverse layer of fibres are discernible, seems to be the remains of the 
infundibulum or expiratory tube (f). 
The direction of the fibres in the cephalic arms is chiefly longitudinal ; the magnified 
figure* precludes the necessity of describing the shape of the horny hooks; their ar- 
rangement in a double alternate series is manifested in some parts of the arms, but 
is still more obvious in the third specimen'!' to be described. 
The second less complete but highly instructive specimen of the Belemnite;^; 
is from the collection of Mr. Pratt; it exhibits part of the muscular mantle ( d ), 
the two fins (e. e ), apparently the infundibulum (f), the ink-bag and duct (w), and 
a considerable proportion of the phragmocone (c). This part is more distorted and 
less entire than in the preceding specimen, but, so far as a comparison can be made, 
presents the same form and structure §. 
The reservoir of ink is situated two lines within the aperture of the phragmoconic 
capsule, which terminates with the same well-defined border ; it is of an oval form 
and jet black colour, with a feeble indication of its original nacreous outer coating : 
the inspissated ink is very hard, brittle and splintering ; when reduced to a fine 
powder it presents a dark brown hue, and, used as a pigment, works as smoothly as 
Roman Sepia, but with a deeper tint. 
The Beletnnitic ink-secretion offers the closest resemblance with that described by 
Br. Buckland from the lias of Lyme Regis, and which he found associated with a 
series of circular transverse plates and narrow chambers, resembling the chambered 
cone within the alveolus of a Belemnite, and from which Dr. Buckland inferred that 
the animal, from which these fossil ink-bags were derived, was some unknown Ce- 
phalopod, nearly allied in its internal structure to the Belemnite, the circular form 
of the septa showing that they could not be referred to the molluscous inhabitant of 
any Nautilus or Ammonite ||. 
The absence of the ink-apparatus in the Nautilus and allied extinct chambered 
Cephalopods adds demonstrative proof, were such required, of the accuracy of Dr. 
Buckland’s negation, whilst the association of the spathose guards with crushed 
phragrnocones, identical in structure with those in connection with the fossil ink-bag 
and muscular parts of the specimens under consideration, and all from the same 
* PI. IV. fig. 2. f PI. v. : PI. IV. fig. 1 . 
§ Near the confused remains of the head in this specimen there is the impression of part of the phragmo- 
cone of another Belemnite. 
|| Philosophical Magazine, 1829. 
