land plants in the Secondary formations, (from the Keuper to the Chalk inclusive;) one half of these are Coniferæ and Cycadeæ, and of this half; twenty-nine are Cycadeæ; the remaining half are chiefly vascular Cryptogamiæ, viz. Ferns, Equisetaceæ, and Lycopodiaceæ. In our actual vegetation, Coniferæ and Cycadeæ scarcely compose a three hundredth part.[1]
The family of Cycadeæ comprehends only two living Genera; viz. Cycas, (Pl. 58.) and Zamia. (Pl. 59.) There are five known living Species of Cycas and about seventeen of Zamia. Not a single species of the Cycadeæ grows at the present time in Europe; their principal localities are parts of equinoctial America, the West Indies, the Cape of Good Hope, Madagascar, India, the Molucca Islands, Japan, China, and New Holland.
Four or five genera, and twenty-nine species of Cycadeæ, occur in the fossil Flora of, the Secondary period, but remains of this family are very rare in strata of the Transition, and Tertiary series.[2]
- ↑ The fossil vegetables in the Secondary series, although they present many kinds of Lignite, very rarely form beds of valuable Coal. The imperfect coal of the Cleveland Moorlands near Whitby, and of Brora in Sutherland, belong to the inferior region of the Oolite formation. So also does the bituminous coal of Buckeberg near Minden, in Westphalia.
The coal of Hoer in Scania is either in the Wealden formation, or in the Green-sand (Ann. des Sciences Nat. tom. iv. p. 200.)
- ↑ I learn by letter from Count Sternberg, (Aug. 1835.) that he has found Cycadeæ and Zamites in the Coal formation of Bohemia, of which he will publish figures in the 7th and 8th Cahier of his Flore du Monde primitif. This is, I believe, the first example of the recognition of plants of this family in strata of the Carboniferous series.
During a recent visit to the extensive and admirably arranged geological collection in the Museum at Strasbourg, I was informed by M. Voltz that the stern of a Cycadites in that museum, described by M. Ad. Brongniart as a Mantellia, from the Muschelkalk of Luneville, is derived from the Lins near that Town. M. Voltz knows no example of any Cyeadites from the Muschelkalk. Stems and leaves of Cycadeæ occur also in the Lias at Lyme Regis. (Lind. Foss. Fl. Pl. 143.)
