life. The vegetation of the period consisted largely of giant species of cryptogamic plants allied to our modern tree ferns, horsetails, and club mosses. To the first class belong the various Coal Measure ferns, such as Spbenopteris, Neuropteris and Pecopteris; to the second belongs the genus Catamites, with jointed and finely-fluted stems. To the third class belongs the Lepidodendron, the stems of which are covered with scale-like markings. To this is closely allied the Sigillaria, with seal-like impressions on the broadly fluted trunk. Stigmaria is a root common in the underclays of coal seams, and is so called on account of its pitted and tuberculate surface. Specimens of all these plant remains may be looked for in the beds of sandstone, shale and fireclay associated with the coals, which themselves are made up of compressed beds of this ancient vegetable growth.
Of animal life specimens of bivalve shells, Anthracomya and Carbonicola, the latter resembling our freshwater mussels, and also fish remains, may be looked for in the same beds; while the Spirorbis pusillus is generally abundant in the limestones near the summit of the Coal Measures. It is likely too that the limestones and some of the shale bands may on careful search be found to contain small bivalved entomostraca such as Carbonia and Estberia.
Permian.—The so-called Lower Permian rocks occupy a broad tract of country extending from Baxterley on the north to Kenilworth on the south; their eastern limit is formed by the ordinary Coal Measures which rise conformably from beneath them; on the west, south, and south-east the tract is bounded by Triassic rocks.
The beds consist of about 2,000 feet of alternations of red, brown, and purple sandstones and red marls, with impersistent bands of breccia and conglomerate. According to Mr. Fox-Strangways,[1] sandstones are conspicuous towards the base, and form a marked feature in the northern part of the district, where they have been quarried at numerous localities about Baddesley Ensor and Baxterley.
The breccias and conglomerates are generally found in the lower part of the series; one band particularly well-marked occurs at about the middle, and forms a bold escarpment at Corley.[2] They are made up largely of pebbles of Carboniferous limestone and chert, among which some of Silurian sandstone have been noted at Exhall. So rich are they in limestone pebbles that they have been extensively quarried and burnt for lime between Fillongley and Over Whitacre.
The higher beds of the series occur between Coventry, Kenilworth, and Warwick, and the sandstones may be seen in various quarries. The beds hereabouts however appear to be largely composed of marls, for near Warwick a boring passed through 700 feet of rock consisting chiefly of marls and thin beds of sandstone.[3]
More recently a boring has been put down at Kenilworth for the
- ↑ 'Geology of Atherstone,' Mem. Geol. Survey (1900), p. 28.
- ↑ For breccias near Polesworth see H. T. Brown, Quart. Jount. Geol. Soc. xlv. (1889), I.
- ↑ Howell, 'Warwickshire Coalfield,' ibid. (1859), p. 31.
