442 J. PrestwicHj Esq., on the 



the last being 25 feet long and 5 feet broad. I procured in these beds only one imperfect cast of 

 an univalve, resembling the Bellerophon found in the Penneystone. 



In the sandstone and shale above the best coal at the Birch leasow pits, Broseley, casts and 

 impressions of vegetables are so numerous as to divide the sandstone into thin laminae, which are 

 easily separated. At Blissers' Hill pit, Madeley, and at the Holywell pits, Malinslee, I also 

 saw some very large casts, the terminations of which I could in no instance discover. Upon 

 several of the impressions of the delicate Sphenopteris imbedded in the rock above the best coal 

 at Broseley, the vegetable tissue of the leaves is preserved, and presents a thin, brown, semi-trans- 

 parent, and elastic filament*. Mr. J. Phiili^js has shown me vegetable remains in the same state 

 from the oolitic series in Yorkshire. Similar fossils, but in less abundance, characterise the strata 

 up to the Penneystone. 



The organic remains contained in this bed of ironstone, are tolerably numerousf and well pre- 

 served ; and are of the greatest geological importance, as marine animal remains largely preponde- 

 rate. Fragments of a few stems of plants, from two to three inches long and from half an inch to 

 an inch in diameter, are the only vegetable reliquiae found in this stratum. The external characters 

 are entirely destroyed, but the cellular texture and the fibres are preserved in the state of soft 

 brown lignite. These remains are often studded with beautiful crystals of blende and caibonate 

 of lime, and are enclosed in the nodules of ironstone. 



The characteristic marine fossil is the Leplcena (Producta) scahr'icula, which is abundant, and is 

 well known as a mountain limestone fossil ; the Spirifer bisulcatus likewise occurs frequently. 

 Several species of Nautilus, Bellerophon, Conularia, Pecten, Orbicula, Unio, Terebratula, Nucula, 

 Globulus, Lingula, and other shells (Appendix C), associated with scales and bones of the 

 Megalichthys Hibberti, and the Gyracanlhus formosux ; likewise remains of Crustacea, new 

 species of Trilobites, and Crinoidea and Coprolites. In the centre of almost every ironstone 

 nodule at Broseley is a dark-coloured, irregularly-shaped spot, which rarely exhibits any traces 

 of organization; but the careful examination of an extensive suite of the nodules shows, that the 

 greater number of these remains are referable to Conulariae, a few to Coprolites, and a less number 

 to the animal matter of the Orbicula. Conulariae abound in this part of the coal-field, though 

 not so plentifully as at Madeley, and are more rarely found at Hadley, Woombridge, and Don- 

 nington. Tiiey vary from a quarter of an inch to two inches in length, and the breadth at the 

 larger end is about a quarter of the length. In none of the numerous specimens which I have ex- 

 amined, could I find any traces of a septum. In two, however, 1 discovered an apparently 

 osseous structure ; white carbonate of lime having infiltrated into the pores, whilst the organic 

 matter remains nearly unaltered, but of a dark brown or black colour. Mr. J. De Carl Sow- 

 erby also pointed out to me a singular character. The striae of some specimens are notched by 

 a set of transverse small furrows, whilst in others the striae are perfectly smooth. This differ- 

 ence in structure he found in examining an ironstone specimen, to arise from the presence or ab- 

 sence of a thin, dark-brown skin or covering, of which the interior striae are smooth, and the 

 exterior denticulated or notched (see Plate XL.). The dark spots in the ironstone are not 



* In the same rock, small dark-brown round flat seed vessels, rather less in size than a span- 

 gle, and retaining a nearly unaltered vegetable texture, frequently abound. 



+ Like, however, the organic remains of the chalk, they occur detached, and require a careful 

 search, unlike those wliich are heaped together in patches, bands, or beds, as the unios over the 

 flint coal at Woombridge, and as the vegetable reliquiae generally. 



