Saunders — Geology of South Beds. 543 



spinnlosa,, Wahl. (labelled Olenus serratus, Sal.), from Carreg-wen, 

 near Tremadoc, 



The Upper beds have long been known as the Malvern shales, 

 and I should have preferred to call the group the Malvern Group, if 

 the lower beds had been found in that locality. It is, however, 

 appropriate that the Dolgelly district, where alone the whole of 

 the Cambrian rocks known in Great Britain are represented, should 

 give a name to one of the groups. 



(To he continued). 



Y. ^ISTOTES ON THE GeOLOGT OF SoUTH BkDS. 



(No. II.) 

 By J. Saunders, Esq. 



SINCE my former communication on this subject, which appeared 

 in the Geological Magazine for April last, (p. 154) I have 

 had several opportunities of re-visiting some of the cuttings, on the 

 Midland Eailway, therein referred to, respecting which some doubts 

 were expressed in reference to the age of the deposits exposed to 

 view, and, as they are now completed, more precise observations can be 

 made than when they were only just commenced. The cutting, 

 south-east from Westoning, (which, in an Editorial note, was sug- 

 gested might be of Tertiary age) exposes a dark heavy clay, which, 

 upon the most rigid examination, furnished not the least trace of 

 rolled fragments of Chalk or flints, or any other substance so fre- 

 quent in the Tertiary clays of this neighbourhood, which would lead 

 to the inference that it had been deposited subsequently to the Cre- 

 taceous era. It, however, contains what would strongly indicate 

 that it is coseval with the Greensand, namely, a continuous band of 

 coprolitic nodules, averaging about a foot in thickness. This layer 

 passes through about one-third of the cutting, and may be traced 

 from its commencement on the north-west side of the hill, passing 

 along the face of the cutting with a gentle dip, until it reaches the 

 level of the line, when it passes out of sight, nor does it re-appear 

 on the south-east side of the excavation. The fossils associated with 

 the nodules are Lamna, Belemnites, Parasmilia, and Terebratulce, all 

 of which are abundant in the coprolite beds at Hexton and other 

 places in the immediate vicinity. Both above and below the copro- 

 lites the clay is identical in character, and must have been deposited 

 contemporaneously with its associated nodules, and, as far as I can 

 judge, it is the equivalent of the bed h of the section given by Mr. W. 

 Whitaker, in the Quart. Journ. Geol. Soc, vol. xxi., 1865, pp. 399, 

 " On the Chalk of Bucks." About the middle of the cutting is a con- 

 siderable accumulation of light-brown coloured drift-sands, that lie 

 in a basin-like hollow, that has been eroded from the summit of the 

 hill. 



The cutting at Harlington, at the north-west side of the hill, facing 

 the Kimmeridge Clay and Greensand strata, exposes a thick bed of 

 heavy dark clay, containing a profusion of selenite crystals, with 



