394 WEDLOCK SHALES OE THE WELSH BORDERLAND. [May I9OO. 



The other exposures on the lower slopes of the west side of the 

 Long Mountain are of a very unsatisfactory nature. The beds dip 

 into the hill at a high angle, and fossils are not very abundant. 



Beds of undoubted Ludlow age occur near Bryn, while those 

 exposed on the road between Leighton Church and Pentre seem to 

 belong to the C.-Lundyreni zone ; the rocks in the big quarry near 

 Pentre are certainly Lower Ludlow. 



(C) Sections South of the Long Mountain. 



(■Ca) Ackley Lane. 



There is an excellent exposure in the zone of C. Lundgreni,, 

 in the lane near Ackley. The rocks exposed here must include 

 almost the whole of that zone ; for, as the beds sweep round 

 the south-western extremity of the mountain, beds with the fauna of 

 the C.-rigidus zone are exposed below them. 



Zone of Cyrtograptus rigidus, Tullb. — At Kingswood 

 several exposures occur: — in the lane, in two old quarries, and 

 in the stream, the fauna being everywhere the same. These beds 

 have yielded Monograptus retroflexus, M. Flemingii var. n, and 

 M. dubius. The presence of M. retroflexus indicates the higher 

 beds of the C.-rigidus zone. 



Zone of Cyrtograptus Lundgreni, Tullb. — The section in 

 Ackley Lane I worked in detail, with a view to determining 

 whether any of the graptolites were characteristic of one part of 

 the zone rather than another, and the accompanying table (Table V, 

 p. 395) shows the result of my work. The beds present no particular 

 features ; they are merely a series of earthy calcareous shales and 

 flags dipping W. 30° N. at a low angle. From these data it would 

 seem that M. Flemingii var. y is particularly characteristic of the 

 lower parts of the zone, while var. S is more abundant in the higher 

 beds. 



Above locality 12 in fig. 8 (p. 393) there is a break in the sequence 

 of exposures ; the next beds seen at Z indicate the presence of 

 the Lower Ludlow. 



Exposures belonging to the C .-Lundgreni zone are seen at several 

 points along the road that runs from Marton through Worthen 

 and on to Westbury. The beds are well exposed at Marton close 

 to the church, where I collected M. Flemingii vars. y & h and 

 M. dubius : these are probably the lower beds of the zone. 



Higher beds are seen on the top of the hill before Brockton 

 village is reached, in Brockton Brook, and also west of Worthen. 

 East of Worthen the zone gradually passes beneath the alluvium, 

 for beds with a characteristic Lower Ludlow fauna are seen in 

 a field immediately above the road at the Plough Inn, and all the 

 other exposures examined farther east were in beds of that age. 



(Cb) Walcot Quarry. 

 The lowest Wenlock Beds seen in the district are exposed north 



