444 J. Prestwich, Esq., on the 



An interesting phenomenon in the distribution of the animal reliquiae in the Penneystone measure 

 is observable at Langley. I had collected from other localities during three summers, a large 

 number of Leptaense, Spirifers, Orbiculae, Conulariae, and Nautili ; and Mr. Anstice had found 

 one specimen of a Cyathocrinites and a few scales of the Megalichthys and Gyracanthus, but in 

 the deep works at Langley, the Penneystone measure, which is usually very regular in its charac- 

 ter, was in one place much changed by an admixture of sand, and the ironstone nodules became 

 lumpy, less numerous, and bad ; and were accompanied by a remarkable increase in the number and 

 variety of the organic remains ; including all the before-mentioned species, together with species 

 of Bellerophon, Nautilus, Nucula, Lingula, Crinoidea, &c. Unfortunately, the quality of the 

 ironstone was so much deteriorated, that that part of the work was soon abandoned. A singular 

 diminution, and, finally, a total absence of fossils, occurs in this stratum in its range northward. 

 (See Diagram, PI. XXXVIl.) 



Above the Penneystone, south of Lightmore, no marine remains have been found. 



The Penney-ironstone measure is immediately succeeded by a stratum of a fine-grained sand- 

 stone, generally ferruginous, and varying from 5 to 10 yards in thickness ; but the fossils, unlike 

 those of the subjacent bed, consist of a most luxuriant land vegetation, including numerous species 

 of Calamites, Sigillaria, Lepidodendron, and Stigmaria. These remains are most frequently found 

 in the partings of the rock, and generally lie horizontally, but in all directions. As usual, the cast is 

 formed of the substance of the matrix, and it rarely, if ever, possesses any traces of vegetable tex- 

 ture ; but the exterior bark is frequently replaced by a thin coating of fine coal. Calamites of se- 

 veral species constitute the prevailing fossils ; and they are generally from half an inch to 4 inches in 

 diameter and from 1 foot to 1 feet in length ; yet owing to their extreme brittleness when first ex- 

 posed, they are difficult to preserve entire. Sigillariae are also common, some of them being of a very 

 large size. One fine specimen, in a quarry near Ketley, measured 10 feet in circumference. It 

 was truncated at the parting of the strata about a foot above the root, which consisted of four taper- 

 ing prolongations, each about 4 feet long. The markings on the surface were nearly obliterated, 

 and the species consequently could not be determined. Specimens of this size, I have always 

 found similarly placed, and universally truncated. They may be observed in the " cow wood" and 

 other quarries of that district, in the sandstones of the " clod coal poundstone " at Castle Green, 

 and in the same measures in the Blisses Hill pits at Madeley. Imperfect impressions of the leaflets 

 of Stigmariae and Lepidodendra can generally be traced. A few varieties of dicotyledonous wood 

 also occur. 



Immediately upon this sandstone reposes the flint coal, in which vegetable impressions are not 

 uncommon. In a pit at Dawley, I found a large upright stem in a similar condition to that of the 

 fossil tree of Cragleith. Its diameter was 1 foot and its height 3 feet ; and it was truncated at 

 both ends. The bark, which was replaced by coal, about a quarter of an inch thick, exhibited no 

 distinct marking. The internal structure was that of coniferous wood, somewhat resembling the 

 Pinites Withami. 



In the hard bituminous shale which in some parts of the field overlies the flint coal, are several 

 bands full of a crushed bivalve shell, and belonging apparently to the genus Unio ; scales of a 

 Hybodus ? and other fishes occur, though rarely. 



To this generally succeeds a bed of hard micaceous shale containing a layer of ironstone nodules, 

 called the white flats, in which are imbedded some very interesting fossils. The characteristic 

 plants are Lycopodiaceae and Equisetaces ; but associated with them are considerable quantities 

 of two or three species of Unio. Scales and bones o( Megalichthys Hibbertii, and Gyracanthus for- 

 mosus, are occasionally met with ; but the most singular and interesting fossils in this stratum are 

 several undescribed Crustacea of the Trilobite family. 



