§ 9. FOSSIL SERPENTS.-Vertebra of large serpents have of late years been found not unfrequently in the London clay at Sheppey and Bracklesham. In the Memoir above cited,* a summary of the osteological characters of the vertebral column of the ophidians forms the introduction to the figures and descriptions of several species and genera of serpents of colossal size which existed during the eocene period. I believe no ophidian vertebræ have hitherto been collected in the Isle of Wight; but from Hordwell, Mr. Searles Wood and Mr. Falconer have obtained several belonging to two species of land-serpents, the one between two and three feet, and the other four feet long. In the eocene clay of Bracklesham many vertebræ of a seaserpent, at least twenty feet in length, have been discovered.† § 10. EOCENE MAMMALIA.-A few remains of palæotheria have been obtained from the compact limestone near Ryde. In a block, lying on the sea-shore, a fine lower jaw with teeth of Palæotherium magnum was discovered by a man employed in breaking stones, during my visit in 1848, but the specimen was so fragile from long immersion in the sea, that fragments of the crowns of the teeth only were preserved. Of a species of anoplotherium several teeth and a portion of the jaws were collected in the quarry at Binstead. The most important additions to the fossil mammalia of the island are the jaws and teeth of a remarkable genus of pachyderms, allied to anthracotherium, from the freshwater strata of Headon Hill, by the Marchioness of Hastings, and described by Professor Owen under the name of Hyopotamus; ‡ and from Hordwell, of the entire "Foss. Rept. of the London Clay," p. 50. † Ibid. p. 61. Two species have been defined: H. bovinus, and H. vectianus." Quart, Geol. Journal," vol. iv. p. 103. cranium and jaws with teeth of a species of palæotherium, and of two allied genera, Paloplotherium, and Dichodon.* From the same inexhaustible mine of eocene treasures, Hordwell Cliff, teeth of the Hyanodon, a most remarkable extinct genus of the dog tribe, have been obtained; this extraordinary carnivorous animal is characterised by the modification of the dental organs, the arrangement and characters of the teeth being altogether peculiar; the last molar in the lower jaw closely resembles a sectorial (scissorlike) tooth of the hyena, whence the name of the genus.† § 11. CRETACEOUS FORMATION (ante, p. 127).--From this extensive series of deposits a great many beautiful examples of the previously known cretaceous fossils, and a few new species and genera of shells have been brought to light by the authors of the memoirs enumerated in the list of new publications, (ante, p. 303,) and by Mr. Saxby, Mr. Beckles, and other collectors. A reference to the papers in the "Quarterly Geological Journal," and an examination of the figures accompanying them, will show what important acquisitions have been obtained during the last three years, especially from the greensand deposits at Atherfield, and mainly by the researches of Dr. Fitton, § 12. PHRAGMOCONE OF BELEMNITELLA, FROM VENTNOR, -Among the interesting fossils collected by Mr. Beckles are three or four specimens, which I have selected for illustration; one of them is a cast in flint of the alveolus, or cavity of the rostrum or guard, of a species of belemnitella, from the chalk downs near Ventnor. It not unfrequently happens when belemnitest are imbedded in flint, that the * "Geol. Journal," vol. iv. p. 17. Two species of hyænodon occur in the eocene strata of France. The fossil called belemnites (vulgo, thunderbolt), is the rostrum, or solid distal termination of the osselet, or internal skeleton of an extinct type of cephalopodous mollusca, allied to the sepiadæ, or cuttle-fish tribe, spathose radiated guard of the osselet, not having been permeated by silex, has decomposed, and left a cavity in the stone, into which projects an elongated conical body, which is a silicious cast of the phragmocone, or chambered LIGN. 38.-PHRAGMOCONE OF BELEMNITELLA, IN FLINT.-Nat. size. (In the cabinet of S. H. Beckles, Esq.) Fig. 1.-Lateral aspect, showing the upper margin or peristome, and the transverse lines produced by the septa. 2.-Ventral aspect, displaying the longitudinal ridge. internal shell. Such is the case in the present instance, which is an interesting specimen, because it distinctly exhibits the upper termination of the phragmocone in belemnitella (fig. 1, a), the arrangement of the transverse septa, and a cast of the longitudinal band on the ventral aspect. (Fig. 2.) The genus belemnitella differs from belemnites, in having a longitudinal slit or fissure in the guard through the extent of the alveolus, or cavity in which the phragmocone is situated, and other important characters.* § 13. PTEROCERA,† FROM ATHERFIELD.-Several beautiful species of this genus of marine univalve shells occur in the lower greensand or neocomian strata at Atherfield, two of which are represented in the following lignographs from specimens collected by S. H. Beckles, Esq. The first is a LIGN. 39-PTEROCERA MOREAUSIANA, FROM ATHERFIELD.-Nat. size. well-known species in the equivalent strata of France, and has been named Pterocera Moreausiana by M. D'Orbigny. * The reader should consult the article Belemnites in the Supplementary Notes, p. 169, of my "Pictorial Atlas of Organic Remains." 1 vol. 4to. 75 plates. 1850. Henry G. Bohn. † Aporrhais, the original name given to this genus by Aldrovandus, is employed by some naturalists, but to avoid confusion it is desirable to retain that generally adopted by the French and English Palæontologists.. The body of this shell is of an oval form, the spire consisting of five whorls, which are finely striated and ribbed spirally; the lip expands into four long curved digitations, the peculiar form of which, and of the aperture of the shell, are well shown in the specimen. (Lign. 39.†) There are three species of pterocera in the lower greensand, which bear considerable resemblance to each other, namely, Pterocera Fittoni, ("Geol. Trans.," vol. ii., Pl. II., fig. 6,) P. Retusa, LIGN. 40-PTEROCERA BECKLESII, FROM ATHERFIELD. ("Geol. Trans.," 2nd series, vol. iv., Pl. XVIII., fig. 22.) and P. Moreausiana, described and figured by M. D'Orbigny. § 14. PTEROCERA BECKLESII.-The other species, lign. 40, in the general aspect of the body and spire, resembles P. Fittoni, but the strong carinated ribs of the body-whorl are crenated in the latter, and smooth and * I much regret that these characters are not accurately expressed by the artist in the figure. † In Rostellaria the upper digitation is not in contact with the spire... |