part 2] PALEOZOIC eocks op the llanuollen district. 191 



which constitute the buffer formation between Ordovician and 

 Silurian in the Bala country. In fact, Miss Gr. L. EUes ^ has 

 expressed the opinion that the Hirnant Limestone is equivalent to 

 the Conway- Castle Grits, the upper part of which she would regard 

 as Llandovery in age. 



List of Fossils from the Ctbn-t-Brain Beds. 



[Fossils found in the Dolhir Beds are marked D, those in the Glyn Grit G. 

 C indicates fossils found on Cyrn-y-Brain, and M on Mynydd-Cricor.] 



J) G Favosites fMonticuliporaJ fibro- 



sus Goldfuss. Common. C. 

 D Heliolites i7iterstincU',s Linnaeus. 



C. 

 D G ' Petraia ' elongata Phillips. C. 

 D Petraia suhduplicata M'Coy. 



Common. C. 

 D Petraia suhduplicata, var. cre- 



nulata M'Coy. C. 

 D G Crinoid-remains. C. 

 D Cf. Caryocystites leitchi Forbes. 



C. 

 D Echinosphaerites cf. haltica 



Eichwald. C. 

 D Phyllopora hisingeri M'Coy. 



Common. C. 

 Pinacopora grayi Nicholson & 



Etheridge. C. 

 T> G Ptilodictya acuta Hall. C. 



Atrypa marginalis Dalman. M. 

 D G Clitainhonites ascendens Pan- 

 der. C. 

 ?Dino'bolus sp. M. 

 D G Leptaena rhoinhoidalis Wilckens. 



Common. C, M. 

 D Lingula sp. C, M. 



Mei'istina crassa J. de C. Sow- 



erby. Very common. C, M. 

 D G Orthis actonias J. de C. Sowerby. 



C. 

 D G Orthis fPlatystrophiaJ hiforata 



Schlotheim. C, M. 

 Orthis (P.) hiforata, var. fissi- 



costata M'Coy. M. 

 Ortliis (P.J spiriferoides M'Coy. 



C?M. 

 D G 0. calligramma (?) Dalman. M. 

 D G Orthis crispa M'Coy. C. 

 D G Orthis (Dalmanella)elegantula(?) 



Dalman. C. 

 D 0. (D.) cf. testudinaria Dalman. 

 D Orthis hirnantensis M'Coy. 



Common. C. 

 Orthis (RhipidoinellaJ cf. mul' 



lochiensis Davidson. C. 



D G Cf . Orthis fPlsesiomysJ porcata 

 (M'Coy). C. 



Ortliis (P.) porcata, YSbV. sladensis 

 (Reed). C. 

 D Orthis (Heterorthis ?J sagittifera 

 (M'Coy). C. 



Parastrophia divergens Hall & 

 Clarke. C. 



Plectainho7iites papillosa Reed. 

 M. 



Plectamhonites cf. papillosa. C. 

 D G Plectainh&nites sericea J. de C. 

 Sowerby. C, M. 



Plectamhonites sericea, var. 

 rhomhica (?) M'Coy. C, M. 



Bafinesquina expansa (?) J. de 

 C. Sowerby. C. 



' Bhynchonella ' sp. C. 



Strophomena antiquata J. de 

 C. Sowerby. C. 



Strophomena siluriana David- 

 son. Common. C. 



Triplecia insularis Eichwald. 

 C. 



? Zygospira sp. C. 



Murchisonia cf. turrita Port- 

 lock. C. 



Murchisonia sp. C. 



Tentaculites sp. C. 



Acidaspis sp. C. 

 D Calymene senaria Conrad (Sal- 

 ter). Fairly common. C. 



Calymene cf. senaria. C. 

 D Chasmops macroura Sjogren. 



Fairly common. C. 

 D Encrinurus multisegmentatus. 

 Portlock. C. 



Encrinurus sp. C. 

 D Illxnus hoimnanni Salter. C. 



Illaenus cf. houmanni. C. 

 ? D Phacops hroiigniarti Portlock. 

 C. 



Phacops sp. C. 



Triniicleus sp. Rare. C. 



D 



D 



Q. J. G. S. vol. Ixv (1909) pp. 183-84. 



