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Fig. 4. Convex upper surface of portion of another recent pen, of the same kind. The structure of figs. 3 and 4 closely resembles that of the fossil species represented at fig. 6, of this same Plate, and also at Pl. 29. fig. 1. and Pl. 30. In all of them, the horny plates are composed of a series of longitudinal fibres, intersected by another series of transverse fibres. The disposition of the transverse fibres is most simple in the recent species; passing obliquely outwards from each side of the central shaft, like the barbs or fibrils in the vane of a feather, and being the most distinct towards the outer margin.

The longitudinal fibres are scarcely visible in the recent species, except where they are collected into fluted fasciculi, Pl. 28. fig. 4. BB.) in those parts which correspond with the marginal bands of the fossil species. (Original.)

C. Central part of the Pen, raised like the shaft of a quill between its fibrils.

Fig. 5. Ink bag of a recent Cuttle fish, dissected by the author at Lyme Regis, 1829, containing its natural Ink in a desiccated state; it is a black shining Jet-like substance, having a splintery fracture, and resembling the substance and fracture of the fossil Ink. Its bulk is not much reduced by desiccation. (Original.)

Fig. 6. Upper convex surface of a fossil pen of Loligo Aalensis from the Lias of Lyme Regis. A.A. the barbs; B.B. the marginal bands; C. axis of the shaft; D. excretory duct of the Ink bag, distended with petrified Ink. (Original.)

* In this specimen we see distinctly the disposition of the marginal bands.

[blocks in formation]

Fig. 7. Upper surface of Fossil Loligo from the Lias of Lyme Regis. A,A, Barbs of the Pen. B,B, Marginal bands. C, Axis of the Pen. d, upper plate of marginal band, having an unusually corrugated surface, which may be the result of imperfect growth of the transverse fibres; if fully expanded they would probably have resembled those of the subjacent Plate at d". (Original.)

d'. Magnified representation of the rugous surface of d. d"". Magnified representation of the second plate of the marginal band, Fig. 7. d".

e. Upper surface of second Plate of the shaft of the pen; here the transverse wavy lines predominate over the vertical straight lines; but both are visible.

f. Upper surface of third plate; here the vertical straight fibres prevail ove, the transverse wavy fibres.

PLATE 29. V. I. pp. 232 and 234.

Fig, 1. Fossil Loligo from Lias at Lyme, in the collection of Miss Philpot, exhibiting nearly the same structure at figs. 6. 7. at Pl. 28. and containing beneath the pen, a very large Ink bag, D. The greater proportionate size of this Ink bag indicates a difference in species from fig. 3. (Mrs. Buckland. Original.)

Fig. 2. Loligo Aalensis from Lyme Regis showing the under surface or concave side, and the duct of the Ink bag distended with Ink. A.A. Barbs or filaments of the Pen; B.B. Marginal bands; C. Axis of Shaft; D. Duct of Ink bag. (Mrs. Buckland. Original.)

The wavy lines here seen between the Ink bag and the apex of the Pen, are the inferior terminations of the successive lamina of growth; each

larger and superior Plate overlapping the edges of the next subjacent and smaller plate. These edges are rendered more irregular by decomposition. d'. Magnified representation of very minute curved lines passing from the marginal band across the shaft, at d.

e. Thin lamina of the white pulverulent substance of a decomposed Plate; it retains partial traces of the transverse wavy fibres.

f. Minute perpendicular filaments prevailing over the transverse fibres of the shaft.

Fig. 3. Fossil Loligo from Lyme Regis, showing the same structure as the preceding figures, in the several portions of the Pen that are preserved; and having its Ink bag distended nearly in its natural shape and place beneath the Pen. (Original.) C.C. Axis of the shaft.

Figs. 4. 5. 6. 7. 8. 9. Fossil Ink bags from Lyme Regis. The membranous sacs and excretory ducts are still preserved, and closely resemble those of a recent Ink bag; see Pl. 28. fig. 5. (Original.)

Fig. 10. Fossil ink bag found by Miss Anning in the Lias near Watchet, Somerset. (Original.)

PLATE 30. V. I. p. 234.

A large fossil pen of Loligo; from the Lias at Lyme Regis. In the collection of Miss Philpot. (Mrs. Buckland. Original.)

AA. Barbs of the pen, proceeding from the outer edges of the marginal bands.

B.B. Marginal bands dividing the bases of the barbs from the internal part or body of the shaft.

C. Axis of the Pen, dividing the body of the shaft into two equal parts.

D. Transverse section across the Ink bag.

d. First or upper plate. This plate is very thin, and smooth, and its structure is obscure, except on the right marginal band at d', where the longitudinal ridges on its surface are very distinct.

e. Upper surface of second plate, marked with broad wavy lines, passing on each side from the axis outwards, across the body of the shaft, and over the marginal bands.

f. Upper surfaces of a third plate, exhibiting minute curved striæ, ascending symmetrically in opposite directions from each side of the axis of the shaft C, and descending towards its margin. These curved striæ are intersected by minute longitudinal straight lines, running nearly parallel to the axis of the shaft. Towards the apex of the shaft at f', the broad transverse curves predominate over the fine longitudinal fibres which lie beneath them. At g, no transverse curves are visible.* (Mrs. Buckland. Original.)

PLATE 31. V. I. p. 240.

Fig. 1. Animal of Nautilus Pompilius, fixed in its shell. The shell is copied from one in the collection of Mr. W. I. Broderip. (Animal from Owen. Shell original.)

n, The Hood, or ligamento-muscular disk that surrounds the head.

p. The digital tentacles protruded from their sheaths.

k. Funnel.

a. b. c. d. e. Siphuncle. The desiccated membrane of

* Herman von Meyer (Palæologica, 1832, P. 322,) mentions the occurrence of ink bags, together with the horny internal shells of Sepia, (Onychoteuthis) in the Lias of Culmbach and Banz.

the siphuncle is laid bare at a. b. c. d. At e, e, and from thence inwards, it is covered by a soft calcareous coating or sheath.

y. y. Collar, projecting inwards from the transverse plates, ⚫ and supporting the Siphuncle. See Note, V. I. p.

243.

Fig. 2. Upper horny mandible of the animal, with a hard calcareous point. (Owen.)

Fig. 3. Lower horny mandible, armed with a similar calcareous point. (Owen.)

Fig. 4. Calcareous point, and palate of upper mandible separated from the horny portion. (Owen.)

Fig. 5. Under surface, or palate of a Rhyncholite, or fossil beak, from the Lias at Lyme Regis, analogous to the

recent specimen, fig. 4. (Original.)

Fig. 6. Upper view of another Rhyncholite from the same stratum and place. Black portions of the horny substance, in a state resembling charcoal, remain attached to its posterior surfaces. (Original.) Fig. 7. Side view of the calcareous portion of an upper mandible, from the Muschel kalk of Luneville. (Original.)

Fig. 8. Upper view of another Rhyncholite from Luneville. (Original.)

(Original.)

Fig. 9. Palatal view of fig. 8. Fig. 10. Calcareous point of an under mandible from Luneville. The dentations on its margin resemble those on the recent mandible, fig. 3, and co-operating with the dentations on the Margin of the upper mandible, fig. 9, must have formed an Instrument (like the recent beak, figs. 2 and 3,) well fitted for the rapid demolition of Crustacea and small Shells. (Original.)

Fig. 11. Under surface of fig. 10.; it is strengthened by

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