Lign. 147. Osselets of extinct dibranchiate Cephalopoda.
(Woodward, Manual, p. 76, pl. 1 & 2.)
| Fig. | 1.— | Belosepia sepioides; 1/2 nat. Eocene. Bracklesham. |
| 2.— | Spirulirostra Bellardii; 2/3 nat. Miocene. Turin. | |
| 3.— | Beloteuthis subcostata; 1/4 nat. Lias. Wirtemberg. | |
| 4.— | Beloptera belemnitoides; 2/3 nat. Eocene. Bracklesham. |
BELOPTERA
Beloptera. (Bd. pl. xliv. fig. 15. Min. Conch. tab. 591.)—Under this name Mr. Sowerby figures and describes a very curious fossil, from the London Clay at Highgate, which seems to hold an intermediate place between the Cuttle-fish and the Spirulirostra. The guard, which is of an oblong form, with an obtuse apex, has the structure of the osselet of the Sepia, and contains in its upper part a phragmocone, the cells of which are very narrow. In strata of the same age, in France, three species have been discovered by M. Deshayes. I allude to these shells, that the attention of the collector may be directed to the search after other examples in our tertiary deposits.
Fossil Calamary, or Squid. Geoteuthis.[406] (Bd. pl. xxviii. xxix.)—The common Calamary (Loligo vulgaris) is so often seen on our shores, that its general aspect must be familiar to all who frequent the sea-side. In this animal, the osselet, or internal support, is a cartilaginous elongated body, which, from its form, is called Sea-pen (Bd. pl. xxviii.); and even this delicate structure is found in a fossil state. In the Lias of Lyme Regis, Miss Mary Aiming first discovered specimens of Sea-pens in juxtaposition with the ink-bag, as in the recent Calamary; and subsequently many similar examples have been found, both in England and on the Continent. Dr. Buckland has given some exquisite figures of these fossils; and his collection contains a matchless series of these most interesting organic remains. In some specimens the ink-bag and its tube or duct, but little compressed, are occasionally met with, having a brilliant nacreous pellicle, the remains of the sheath, attached to the surface. The ink-bag is sometimes of considerable magnitude; specimens have been found at Lyme Regis nearly a foot in length.[407] The circumstance of the ink-bags being generally full of sepia admits of the inference (as Dr. Buckland with his wonted acumen remarks), that these individuals died suddenly; for their living analogues reject the inky fluid upon the least approach of danger. The perfect condition of the bag proves also their instantaneous enclosure in the deposit, for the distended membrane would otherwise have burst from decomposition, and the contents would have escaped. The fossil marine reptiles, the Ichthyosauri, &c., with which these fossils are associated, present similar phenomena, as we shall hereafter have occasion to remark, and strengthen the probability, that swarms of the inhabitants of the Liassic ocean were suddenly destroyed, and imbedded, on the area now occupied by their remains.
[406] Geoteuthis has hooks on its arms; hut, being a Calamary (Teuthid), it would probably have unequal arms.—Mr. Woodward.
[407] The large ink-bags figured by Dr. Buckland (Br. Tr. vol. i. pp. 372-379, pl. xliv′.) belonged to the great Geoteuthis Bollensis, of Schuble.—Mr. Woodward.
In the cream-coloured limestone, of Solenhofen, so rich in organic remains of the highest interest (Wond. p. 578), the soft parts of naked Cephalopoda have also been discovered. I have figured, [Lign. 140], a beautiful specimen obtained by the late Count Münster, which exhibits an imprint of the body, the arms and tentacles being represented by ten double rows of horny hooks, which precisely resemble those of Belemnoteuthis. M. D’Orbigny supposes that the original animal closely resembled a recent decapod called Enoploteuthis leptura.