236 A POPULAR SKETCH OF THE 



ally be found in the limestone shale, similar to those of the coal 

 measures. I have seen a few from the limestone beds in the lower 

 part of the shale at Turnditch and Ashford. The marine remains 

 consist of Corals, Crinoidea, Crustacea, shells, and fishes' teeth. 

 The Corals are very abundant in particular places, and are fre- 

 quently preserved with the utmost beauty, looking as perfect as if 

 fresh from our own seas. Tubipora, Syri?igopora, Turbinolia, Cya- 

 thophyllum are among the most common genera. There are many, 

 however, which have not yet been accurately figured or described, 

 and with whose names and affinities I am unacquainted. The Cri- 

 noidea occur in particular beds in the most enormous abundance, 

 and are well known from the sections of their stems producing the 

 remarkable figures in the encrinal or Derbyshire marble. Rocks, 

 many yards in thickness, are in some places literally composed of 

 the fragments of the stems of these animals ; and what is remark- 

 able is, that while millions of stems may be seen, it is rare to find 

 even a fragment of a head. In the neighbourhood of Ashford, how- 

 ever, the heads seem more abundant. Many genera of these ani- 

 mals are found ; but for figures and descriptions of those peculiar to 

 the mountain limestone, as well as of the fossils of that formation 

 generally, the reader must consult Professor Phillips's Illustrations 

 of the Geology of Yorkshire, Vol. II. The Crustacea consist of 

 Trilobites, (of a different species from those of Dudley), many of 

 which are found in the black marble at Ashford* and its accompany- 

 ing rotten-stone. The shells of the mountain limestone are, I be- 

 lieve, wholly marine, and are of many genera and species. In the 

 quarry at Turnditch may be found one or two species of a bivalve, 

 which I believe to be a Posidonia, as also, both there and at Ash- 

 ford, Orbicula, Lingula, and other remarkable shells. The most 

 common and characteristic bivalves are the Producta, many species, 

 varying in size from that of a nut to that of a man's head, lying in 

 the rock, sometimes, like beds of oysters ; the Spirifer, many species, 

 never exceeding the size of a fist, and remarkable for two internal 

 spiral appendages, which are sometimes perfectly preserved ; and 

 the Terebratula, a smaller shell, some species of which assume the 

 most singular shapes. Of univalves, there may be found the Mela- 

 nia, the Natira, the Pleurotomaria, and others. The Euomphalus 



* For specimens of the very numerous and interesting fossils of the neigh- 

 bourhood of Ashford, those desirous of them may apply to Benjamin Sellers 

 of that place — a remarkably civil and intelligent man, who has the best col- 

 lection of limestone fossils in the county, and (a virtue rare in fossil-dealers) 

 i* moderate in his charges. 



