390 PROCEEDINGS OF THE GEOlOGICAl SOCIETY. [May 10, 



HicliB, Conocoryplie Lyell'd, Hicks, Microdiscus sculptus, Hicks, Ag- 

 nostus camhrensis, Hicks, Protosjjongia fenestrata, Baiter, TTieca an- 

 tiqua, Hicks, and Paradoxides ITarhiessi, Hicks. 



The yellowish-coloured sandstones and shales are well seen on 

 their line of strike in most of the headlands which intervene between 

 Forth Clais Harbour and Caer-bwdy. The principal spot from 

 which fossils have been obtained is the second headland E. of Forth 

 Clais Harbour. The same rocks can be seen also between Folly and 

 Trelerwr. Their thickness amounts to about 150 feet ; and on the 

 K.jS'.W. side of the axis their equivalents occur in a nearly allied 

 form, being yellowish -grey sandstones. 



Succeeding these are grey rocks with purple bands, which pass 

 upwards into purple and red sandstones and shales ; and from these 

 LinguleUa ferruginea, var. ovaJis, Conocoryphe, solvensis, Paradoxides 

 Harhnessi, and several of the other species have been obtained be- 

 tween Solva and Whitchurch. The total thickness of the two series 

 on the S.S.E, side of the axis is about 700 feet. On this ,side of the 

 axis these rocks are intersected by lines of faults, which run parallel 

 to their strike ; and one of these extends from the coast a little S. 

 of Folly through Trelerwr, These faults have downthrows on tlieir 

 S.S.E. side, which have reduced very materially the absolute thick- 

 ness of those rocks on this side the promontory. 



On the E. side of Ramsay Sound, and on the ^N'.N.W. side of the 

 axis, the equivalents of the grey and purple sandstones do not seem 

 to have been affected by faults ; and here they have a thickness of 

 about 1500 feet. 



On this side of the ridge also the grey and purple sandstones have 

 their representatives in the form of grey, purple, and red flaggy 

 beds. 



On the S.S.E. side the grey and purple sandstones have, resting 

 conformably upon them, grey grits, which contain Paradoxides 

 aurora, Salter, and Conocoryphe hufo, Hicks ; and these two forms 

 have not, up to the present time, been discovered in strata which 

 underlie or overlie the grey grits. Agnostus camhrensis and Theca 

 antiqua have also been obtained from these grey beds. These two 

 species also occur in the underlying rocks ; but they have not yet 

 been met with in deposits higher than the grey grits. Discinapi- 

 leolus, Hicks, and Oholella sagittalis, Salter, are also found in the 

 grey beds. They likewise occur in the underlying purple strata, and 

 they extend upwards through the Menevian group. 



LinguleUa ferruginea is also found in the grey beds ; and this form 

 has the widest range of any of the fossils that have been obtained 

 from the purple and green rocks of the St. David's promontory. It 

 occurs in the lowest fossiliferous zone which has hitherto been dis- 

 covered, and it extends through the Menevians. Theca penultima. 

 Hicks, also occurs in these grey rocks ; and this is the lowest 

 horizon from Avhich it has been procured. Its range seems limited, 

 as it has not been met with above the lower portion of the Mene- 

 vians. 



On the N.N.W. side of^the axis, on the E. shore of Ramsay 



