Vol. 62.] ROCKS OF WESTERN CARMARTHENSHIRE. 60? 



lane and another in the dingle to the north-west. They are traced 

 westward across the hill north of Blaenweneirch, and have been 

 extensively quarried for road-metal on the side facing Henllan- 

 Amgoed. Some of the beds here, as well as at Blaencediw Quarry, 

 are crowded with Ortliis Carctusii, Salt. Occasional trilobite- 

 fragments have also been found here. At this quarry the fossil- 

 bearing bands weather buff and mottled grey. 



A short distance south of the quarry these beds appear to be 

 faulted-out, and are not seen in the dingle to the west; but on the 

 small ridge south of Henllan Church they come to the surface again r 

 and the lower beds are exposed in a quarry at the southern 

 extremity of that ridge. Yew fossils occur here, consisting of 

 Ortliis Carctusii, Salt., and doubtful fragments of Dendrograptus. 



Along the western flank of this ridge the grits disappear, partly 

 by faulting, and partly by passing under higher beds. 



(4) (9ri7zis-Mudstone and Dictyograp)tus-Beds. — At 

 Blaencediw Quarry the grits are seen passing up into gritty black 

 mudstones abounding in Ortliis Carctusii. Some hard bands in 

 these are crowded with graptolites of Dictyograptus and Dendro- 

 graptus types. A small collection of fossils from this section 

 was submitted to Miss G. L. Elles, D.Sc, and she identifies the 

 following : — 



Callograptus radiatus, Hopk. 

 Callograptus Salteri, Hall. 

 Callograptus Scdteri, var. attenuatus, 



Dictyograptus Homfrayi, Hopk. 

 Climacograptus implicatus, Hopk. 

 Dendrograptus flexuosus, Hall. 



Elles MS. Dendroqrajrtits sp. (possibly new). 



Dictyograptus cf. Homfrayi. Hopk. Ortliis Carausii, Salt, 



(possibly new). Lingula sp. 



There are several faults in this quarry, but none appears to be of 

 great extent. 



Farther up the dingle, the beds become more flaggy, and gradually 

 change their texture, passing up into finer-grained mudstones with 

 Tetragraptus at no great distance. These flaggy beds contain 

 Callograptus, etc., in abundance. 



Ortliis-m\idstones come to the surface on the road near Penlanfach, 

 where they are fairly fossiliferous, but they have not yielded any- 

 thing besides Ortliis Carausii, Salt. Farther south, flaggy beds are 

 seen on the roadside lying nearly horizontal. These have yielded 

 an Orthoceras sp. (possibly new), Lingida sp., Ogygia marginata, 

 Trinucleus sp., Siphonotreta (?), etc. 



There is a good section of black shales and mudstones along the 

 lane leading to Henllan grit-quarry. The beds are somewhat flaggy 

 in places, but are disappointing as regards their fossil contents. In 

 the lower part of the road there are some lenticular masses of 

 weathered grit packed with Ortliis Carausii, Salt. ; Orthoceras sp.,. 

 Theca sp., and some obscure dendroid forms also occur. 



Higher in the series are some shales and flags rich in trilobites. 



