The upper part of its 

 course, as far as the 

 hedge which divides 

 the moorland from the 

 coppice and cultivated 

 land below, is occupied 

 by the various members 

 of the Talerddig Group, 

 which are well exposed 

 and dip into the hill at 

 25°. In this section, the 

 thickness of the lowest 

 shale-band of the Taler- 

 ddig Group, which is 

 not visible in other parts 

 of this northern and 

 western area, is proved 

 to be about 200 feet. 

 At its base, (1) in fig. 4, 

 20 to 30 yards below 

 the hedge, there occurs 

 a grit 1 foot thick ; and 

 a thin shale-band imme- 

 diately above it yields 

 Monograptus Marri (C), 

 M. nudus(C), M.jjriodon, 

 M. subconicus, and 31. 

 gemmatus (f). 



Gelli Group (Bb).— 

 The upper strata of the 

 underlying Gelli Group 

 consist of thinly-bedded 

 shales and flags dipping 

 south - eastward. They 

 yield an occasional 

 graptolite, such as M. 

 nudus and 31. Marri. 

 For about 50 or 60 yards 

 above and below the road 

 which leads to the farm- 

 house of Gelli, there are 

 no exposures ; but when 

 the strata appear once 

 more, they consist of 

 dark-bluish mudstones, 

 thickly bedded and 

 weathering spheroidally, 

 with some more thinly- 

 bedded shales and occa- 

 sional flags. These rocks, 

 which resemble litho- 

 logically the Gelli Beds 



