Part of Gloucestershire and Somersetshire. 355 



In the ranges of the transition beds, now noticed, the same organic remains 

 are in general to be observed as occur in the environs of Tortworth ; 

 I have not, however, met with either the Calymene variolaris, or the non- 

 descript trilobite of that district ; while the Asaphus caudatus is common, and 

 in one instance the Calymene of Blumenbach has occurred, namely at Aston 

 Ingham adjoining May hill, where it was discovered by the Rev. Dr. Cooke. 

 Chain coral, on the other hand, is much more abundant. Portions of the 

 Cyathocrinites rugosus are also occasionally met with. 



The beds of the transition series appear under different angles of elevation, 

 in their line of contact with the old red sandstone on the west, dipping in some 

 parts at a low angle toward that quarter, as at the north-eastern foot of Per- 

 rystone hill ; while in others, as at Aston Ingham, they approach to the vertical 

 position. 



§ 35. On the other hand, the old red sandstone, in its line of contact with 

 the transition tract, is generally disposed in strata approaching to the horizon- 

 tal position, dipping 15° to 30° toward the west; but in receding from the 

 transition district, the strata gradually obtain a higher angle of elevation, even 

 so high as 70° in the sandstone ridge east of Mitchel Dean ; corresponding, 

 in this respect, with the arrangement already observed on the right bank of 

 the Severn, in connexion with the Forest of Dean (§ 17.). 



In the lower strata of the old red sandstone, adjacent to the transition rocks, 

 may be casually observed a few beds of limestone conglomerate, composed of 

 irregularly angular pieces of limestone and slate-clay compacted by a marly or 

 calcareous paste, and locally known by the name of cornstone. Similar beds, 

 and also a few of limestone, were met with in the lower strata of the old red 



grayish, yellowish, and greenish, as are displayed by the old red sandstone of the sedimentary 

 class ; these sandstones likewise being either nearly free from mica, or more or less micaceous, 

 particularly on the planes of separation. 



These beds appear to constitute the mass or nucleus of May hill, Huntley hill, and Nott's hill ; 

 being occasionally separated by thin beds of clay or sandy micaceous slaty clay, in some places 

 penetrated with calcareous matter, and more or less firm and consistent. 



The impre.ssions and casts of organic remains occur in the coarse grained sandstone, as well as 

 in the finer grained, and in the slate-clay ; and the same coralliform protuberances that are so 

 often met with in those of the Tortworth district appear on the surface of both. 



The conglomerates and sandstones thus found in the transition period, might perhaps by some 

 geologists be denominated gray-wacke. But if we are to speak a language that shall be gene- 

 rally intelligible, it becomes necessary to confine the use of that term, and of gray-wacke. slate, 

 strictly to such rocks as possess a compound mechanical structure, with a base of clay-slate 

 either pure or quartzy. The evils arising from a loose application of these terms are so sensibly 

 felt, that the word gray-xoacke has become, in a manner, the opprobrium of geology. 



