Lign. 146. Horny rings and hooks of Belemnoteuthis antiquus.
| Fig. | 1, 3. | —Detached hooks (natural size). |
| 2.— | Three hooks with attached horny rings: from a specimen inthe possession of Mr. Cunnington. | |
| 4.— | Part of one of the arms, showing four hooked spines. | |
| 5.— | Transverse section of the distal part of the osselet of Belemnoteuthis, exposing the apex of the chambered shell in the centre, surrounded by the radiated osselet, a (magnified four diameters). |
From the extraordinarily perfect condition of the Belemnoteuthis here figured, which of itself exemplifies the essential parts of its structure, a brief description will suffice. The body is of an elongated form, with a pair of lateral fins, two large sessile eyes, eight uncinated arms, and a pair of armed tentacles; each arm was furnished with from twenty to forty pairs of hooks, placed alternately. Like the Sepia it had a pigmental sac or ink-bag, which is generally found filled with the inspissated secretion. The inferior part of the body is of a conical form, and contains a brown horny osselet, with a siphunculated phragmocone, that terminates in a guard or rostrum of a fibrous structure.
[In the recent genus Onychoteuthis, the tentacles alone are armed with claws; Enoploteuthis has claws both on the arms and on the tentacles, but the latter are long and feeble, and the hooks are confined to their extremities. The extinct Belemnoteuthis (like the Acanthoteuthis of Solenhofen, Lign. 140) had eight nearly equal arms, the dorsal pair being rather smaller than the rest; each arm was furnished with twenty to forty pairs of hooks, forming a double, alternating row. The tentacles were not longer than the arms, and like them had a double series of hooks extending from their bases to the points. In all essential points of structure, the Belemnoteuthis is most nearly related to the Calamaries (Teuthidæ), but, in consequence of the prolongation of its pointed shell posteriorly, the fins become lateral (as in Sepiola and Sepia), instead of terminal. Whilst the complicated (chambered) structure of its shell, and the peculiar character of the tentacles, show that it must be regarded as a type distinct from and equal in importance to the Calamaries. It cannot be doubted that the Belemnite and Conoteuthis present similar conditions of the soft parts; and the four genera will form the Family Belemnitidæ. The normal position of these animals in the sea is horizontal, whilst that of the Nautiloid genera must have been vertical, with the head downwards.—Mr. Woodward.]
The fossils which have afforded this unexpected and highly interesting illustration of the nature of the extinct animals of this Order have been obtained by closely examining the shales in which they abound, and, before removing the solid osselet, carefully searching the surrounding stone for traces of the more perishable parts. The attention of the collector can scarcely be too often directed to the necessity of examining the surrounding matrix before extricating a fossil from its bed.
