4thly. The ink-bag, and its inspissated fluid, sepia; (Bd. pl. 44′, figs. 7, 9.)

Lign. 143. The structure of the sherry parts of the Belemnites Puzosianus.
Oxford Clay. Christian Malford. (1/4 nat. size.)

a, a. The dorsal basilar processes of the phragmocone.
b, b. Upward extension of the attenuated osselet.
c. Siphunculus.
d. Phragmocone: the transverse lines indicate the septa.
e. The capsule or outer investment of the guard.
f. The distal part of the phragmocone.
g. The alveolus or cavity in the guard.
h. Vertical section of the guard.
i. The solid part of the rostrum or guard.
k. The sulcus or groove on the ventral aspect of the rostrum.
l. Shows the continuation of the capsule, in section, continued from e.
m. Diverging parallel striæ observable between the dorsal processes of the phragmocone.
n. Transverse section of half the diameter of the radiated structure.

Lign. 144. Very perfect specimen of Belemnites Puzosianus.
Oxford Clay. Christian Malford, Wilts. (1/6 nat. size.)