The flagstones of Caithness and the Orkneys have afforded much more distinct evidences of the Devonian flora. According to Mr. Salter,* we have here the stems and roots of Conifers in abundance, with remains of Lycopodiaceous plants, not altogether dissimilar from some portions of the rich Devonian flora of the Thüringerwald, collected and described by Richter and Unger.† In the "Yellow Sandstone" of Knocktopher, near Kilkenny, which is usually classed as Upper Devonian, ferns (Cyclopteris Hibernica), Lepidodendron, Lepidophyllum, and Stigmaria occur in profusion, asso ciated with remains of Holoptychius, Pterygotus, and an Anodonta-like shell. In North America also plant-remains are frequent in the Devonian strata, and Lepidodendron occurs low down in the series. Prof. Dawson § has recognised coniferous wood in the Devonian rocks of Gaspé, Canada Zoophytes, &c.-The Corals and Crinoids are numerous, and many of the genera are found also both in the Silurian and the Carboniferous rocks. Alveolites, Favosites, and * Quart. Journ. Geol. Soc. vol. xiv. p. 72. See also Hugh Miller's Testimony of the Rocks." +Vienna Acad. Transact. vol. xi. Report Brit. Assoc. 1852, rep. sect. p. 43. See also Prof. Harkness's paper on the "Occurrence of Scalariform Tissue in the Devonian Rocks of Ireland." Edinb. New Phil. Journ. vol. iv. p. 65. § Proceed. Americ. Assoc. 10th meeting, p. 174 For figures and descriptions of the fossil invertebrata of the Palæozoic rocks of Cornwall, Devon, and West Somerset, the student must consult Prof. Phillips's able "Report Pal. Foss.," &c., 1841; and the Memoirs by Sedgwick, Murchison, Lonsdale, and Austen, in the Geol. Transact. 2nd ser. vols. v. vi., &c. The Devonian Corals of Britain form the subject of a beautiful Monograph, by Milne Edwards and Haime, pubished by the Palæontographical Society, 1853. Agassiz's "Poiss. Foss." and Hugh Miller's "Old Red Sandstone" and other works illustrate the Devonian fishes. The Devonian fossils of Germany may be studied in the special Memoirs by D'Archiac and DeVerneuil, Richter and Unger, Romer, the Sandbergers, Geinitz, &c.; those of France are illustrated in many papers in the Bulletin and Mémoires of the Geological Society of France; and those of Russia have been described by D'Orbigny, and beautifully figured in the "Geol. Russia." Hall, Vanuxem, and others have well illustrated the Devonian fossils of North America. Several Devonian fossils are well figured in Lyell's "Manua'," 5th edit., and in Murchison's "Siluria." Cyathophyllum are common in the Mountain-limestone, the Devonian marbles, and the Upper Silurian of Dudley. The crinoideans comprise several genera, especially Cyathocrinus (p. 664) and Hexacrinus. Pentremites and Echinosphærites also occur. The bryozoa also are well represented in the Devonian rocks. Mollusca.-The shells in some districts are very numerous, consisting of many genera of gasteropoda; as, Euomphalus, Loxonema, Pleurotomaria, Murchisonia, &c.; and acephala, as Avicula, Cucullaa, Megalodon, Nucula, &c. But the most remarkable feature in the conchology of this epoch is the abundance of the ancient types of brachiopoda. In the British Devonian strata alone have been determined of Athyris 7 species, Leptana 8, Orthis 12, Rhynchonella 19, and of Spirifer 27. Of the higher order of molluscous animals, species of five genera are met with in Devonshire. The most common belong to Orthoceras, Cyrtoceras, Goniatites,* and Clymenia.t The Orthoceratites in the limestones of Devonshire often attain a large size. The shell is commonly changed into white calcareous spar, which in sections forms a beautiful contrast with the red hue of the surrounding rock. Two species of Nautilus are found in Devon, and five species of the heteropodous Bellerophon. 8. CRUSTACEANS OF THE DEVONIAN SERIES.-In this formation the chief paleozoic type of Crustaceans, the Trilobite, is present in considerable numbers, though not rivalling the myriads that are imbedded in the Silurian rocks. Medals, p. 482. † Medals, p. 473. Polished slices of marble marked with sections of Orthoceratites are sold by the lapidaries of Torquay and Teignmouth. Medals, p. 474. The curious bodies, termed "Beekites," which are found in the New Red Conglomerate of Torquay, appear to have been rolled fossils of the Devonian limestone, which have been coated with chalcedony whilst in the conglomerate, and afterwards decomposed to a greater or less extent. See Rep. Brit. Assoc. 1856, sect. p. 74. The Phacops is a common form; the spinose Homolonoti* are characteristic ; and a peculiar trilobite, termed Brontes flabellifer, has hitherto been found only in the Devonian deposits. Pterygotus.-A large species of an extinct genus of crustaceans, of a low type, occurs in the Devonian sandstone of Forfarshire, Herefordshire, &c.; and fragments of the carapace or shell have long been known to collectors as "petrified Seraphims," the name applied to these fossils by the quarrymen, from their fancied resemblance to the conventional figures of cherubs.† The first specimens which threw light on the nature of the original were discovered by Mr. Hugh Miller at Balruddery. The carapace of this animal forms a somewhat semicircular shield, and the long part of the body is protected by a succession of transverse plates, terminated by a caudal flap.‡ The claws resemble those of the common lobster. The crustaceous covering, or shell, is ornamented externally with circular and elliptical markings, which give it an imbricated, scaly, and somewhat feathered appearance: and it was the imprints of this surface that produced the enigmatical fossils to which the workmen ascribed a celestial origin! Some specimens in dicate a total length of eight feet. Pterygotus occurs also in the uppermost of the Silurian deposits; and Eurypterus, an allied genus, occurs both in the Upper Silurian and in the Carboniferous rocks. Some of the small bivalvular entomostraca occur also in the Devonian rocks, such as the Leperditia; § and a great group of schists *Lyell's "Manual," p. 429. + Miller's "Old Red Sandstone." See Lyell's "Manual," 5th edit. p. 420, for a restored figure of this animal, by Prof. M'Coy; and the Quart. Journ. Geol. Soc. vol. xii. p. 28, for a figure of Himantopterus (a closely allied form), by Mr. Salter; see also Salter, ibid. vol. viii. p. 386, and Agassiz, "Foss. Vieux Grès Rouge," p. xix. By the kind permission of Sir R. Murchison, the Editor can also refer to p. 155 of the new edition of "Siluria," now in the press, for a restored figure of Pterygotus, by Mr. Salter. § Annals Nat. Hist. 2nd ser. vol. xviii. p. 89 in the upper part of the series is so full of the shells and casts of entomostraca, hitherto supposed to be Cypridine, that they are known as the "Cypridinen-schiefer." It is highly probable, however, that these entomostraca will prove to have little or no relation to the Cypridina of M. Milne Edwards, when carefully examined by crustaceologists. 9. FISHES AND REPTILES OF THE DEVONIAN SERIES.M. Agassiz has determined no less than one hundred species of fossil fishes from the Devonian formation, in which, not very many years since, a few doubtful scales, discovered in Forfarshire by the late Dr. Fleming, were the only known vestiges of this class of vertebrated animals. In the British series there are upwards of ninety species, belonging to about thirty-five genera. Of these, the most characteristic A flattened specimen showing the dorsal surface. (One-fourth the nat. size.) are the Cephalaspis, Pterichthys, and Coccosteus, which form a group of extinct genera, that have only a few representatives in the uppermost portion of the Silurian formation below, and noue in the Carboniferous rocks above; nor, except by distant and faint analogies with existing fishes, can these remarkable organisms be brought within the pale of zoological arrangement. These ichthyolites agree in one general character, that of having relatively enormous osseous plates or escutcheons covering the head and anterior portion of the body. Cephalaspis.*-In the extraordinary genus of fishes, named Cephalaspis (Head-buckler) by M. Agassiz, the head is covered by a broad and thin buckler or shield of bone.† The scales of the tail formed elevated bands, and the rays of the fins were covered by the membrane which elsewhere surrounded them. From the large size of the plate forming the cover of the head, its lamellar structure, and crescentlike form, terminating backwards in two horns or points, detached specimens were formerly supposed to belong to trilobites or some other crustaceans. The body is covered with scales, and the shield is sometimes ornamented with radiated LIGN. 185.-CEPHALASPIS LYELLY. Lateral view, showing the produced dorsal lobe of the tail. markings, as in Cephalaspis ornatus and C. verrucosus. Numerous remains of these fishes have been found in the Devonian strata of Herefordshire, Scotland, and Russia. Mr. *Medals, p. 610. + Huxley; Geol. Proceed. January 6th, 1858 Quart. Journ. Geoi. Soc. vol. xiv. p. 48. |