1871.] HARKNESS AND HfCKS ST. DAVID's PROMONTORY. 385 



found both at Dolgelly and in Pembrokeshire, about a hundred feet 

 above the lowest black Lingula-slates." 



Respecting the discovery of another form, Paracloocides Davidis, 

 Salter, in Pembrokeshire, the late Mr. Salter has described thia 

 species, and named the locality whence it has been obtained*. 



In this memoir a Table is also given of the strata which make up 

 the " Lingula-flags in Wales ;" and Mr. Salter has described the 

 lower portion of this series as a " thick mass of black shales very 

 uniform in its upper part, but with hard sandstones in the lower, 

 probably accumulated in a deep sea." The fossils of the Lower Lin- 

 gula-ilags are stated to be " LinguJella, rare, Olenus, common, Ag- 

 nostus, common, Paradoxides Davidis" f. 



Subsequently Mr. Salter, in a communication entitled " On some 

 New Fossils from the Lingula-flags of Wales," described and figured 

 several new forms of Trilobites, a Theca, and a large Sponge ob- 

 tained from the dark-coloured rocks of Porth-y-Rhaw by Mr. 

 Hicks t- 



In this memoir a section is given of the fossiliferous rocks, show- 

 ing their relation to the purple and green sandstones on which they 

 repose. 



In 1865 Mr. Salter alludes to the occurrence of " Some additional 

 Fossils from the Lingula-flags ;" and a note on the genus Ano- 

 2iolenus is appended to this communication by Mr. Hicks §. The 

 lower portion of these Lingula-flags affording the additional fossils, 

 and also those previously referred to, were designated by Messrs. 

 Salter and Hicks, in a paper read at the British Association in 1865, 

 the " Menevian group." 



In 1867 a new form of Lingulella (L. ferruginea, Salter), from the 

 Lower Lingula-flags of St. David's, was described ; and the occurrence 

 of a variety of the same, Lingulella ferruginea, var. ovalis, Hicks, 

 which had been obtained from the underlying red rocks, was al- 

 luded to ||. 



In this communication of Messrs. Salter and Hicks we have the 

 first indication of the presence of fossils in the purple and green 

 rocks of the St. David's promontory, upon which the Lower Lingula- 

 flags are superposed. 



In 1868 Messrs. Salter and Hicks gave an abstract having refer- 

 ence to the occurrence of some new fossils from the Menevian group 

 (Lower Lingula-flags); and in 1869 a detailed description was 

 given of these fossils^. 



The discovery of fossils in the dark-coloured Lower Lingula-flags 



* Quart. Journ. Geol. Soc. vol. xix. p. 275. 



t This description of the Lower Lingula-flags was correct so far as then 

 recognized in North Wales ; but it does not include that very important portion 

 at the base, which has since been separated by Messrs. Salter and Hicks, and 

 named the Menevian group. Paradoxides Davidis belongs to this group, and 

 should not be associated with Olenus, the typical genus of the Lingula-flags 

 proper. 



I Op. cit. suprh, vol. xx. p. 233. § Op. cit. supra, vol. xxi. p. 477. 



]| Op. cit. supra, vol. xxiii. p. 339. 



^ Op. cit. supra, vol. xxiv. p. 519, and xxv. p. 51. 

 VOL. XXVII. PART I. 2 K 



