Lign. 161. Hamites, etc. from the Chalk-marl.
| Fig. | 1.— | Hamites cylindraceus, with part of the shell. (M. D’Orbigny.) |
| 3.— | Baculites baculoides, with the mouth entire. Hamsey. | |
| 3.— | Part of the stem of the same species, showing the sinuoussepta. A detached septum is figured above. | |
| 4.— | Ptychoceras Emericianum. (M. D’Orbigny.) |
BACULITES.
Baculites (staff-like). [Lign. 161], figs. 2 and 3.—This, as the name implies, is a straight, elongated, conical, chambered shell; the upper part is destitute of septa, and probably contained the body of the animal.
In my early researches in the Chalk-marl of Hamsey, I discovered numerous solid, oval, and cylindrical pipes of marl, with scarcely any vestige of organic structure, whose origin it was impossible to determine. At length I found the specimen, [Lign. 161], fig. 2, which showed the perfect aperture of a chambered shell; and afterwards I found portions which displayed the foliated septa. (Foss. South D. tab. xxiii. figs. 5, 6, 7.) The Baculite, when perfect, is elongated to a point; the septa are very numerous and foliated; the siphuncle is situated on the margin. I have a splendid specimen from the Chalk of France, (collected by M. Alex. Brongniart,) which is composed of distinct casts of the cells, held together by the deep inflections of their margins, in the same manner as are the sparry casts of Ammonites, previously described.[421]
[421] See Bd. pl. xliv, fig. 5.
The Galt, near Folkstone, abounds in fossils of the above genera, principally of Hamites; and the nacreous substance of the shells is very often preserved. From the Chalk-marl near Dover, Southbourn, Ringmer, and Southerham, near Lewes, and from Clayton, near Hurstpierpoint, in Sussex, I have obtained examples of several species.
SCAPHITES.