198 



Mr. Bowman on Silurian Rocks west of Abergele. 



A little south of this quarry, on the road from Bettws Abergele to Garthewin and 

 LlanfairTallhaiarn, the blue clay-slate (not fissile) again occurs ; and in the heaps 

 cut away to form the road I found abundance of fragments of small Encrinites, 

 spiral univalves, bivalves, etc. They seemed to lie in layers, and are much decom- 

 posed from exposure, the spaces they have occupied being coated with a dark 

 brown dust. Going down to Garthewin, the stratification is thinner and better 

 defined, the dip about forty degrees to the north, and the rock decomposes into 

 long thin splinters, but I saw no fossils. 



Garthewin surprises the stranger by the secluded beauty of its situation among 

 wooded slopes and bright green pastures. In adjoining walls I observed the taper- 

 ing fossil (Orthoceras ?), already noticed as seen at Nantglyn, etc. From Garthe- 

 win (my most southern point) I turned east to the little village of Llanfair Tall- 

 haiarn, etc., then north to some levels where an adventure for lead-ore is now 

 carrying on, called Bronhaylog Upper and Lower Levels. In heaps of the excavated 

 blue slate I found, chiefly in layers, abundance of joints and broken stems of small 

 Encrinites and minute shells and other fossils, in general exceedingly sharp and 

 clear and quite free from oxidation. They had not lain many days on the surface. 

 Among them I saw a few indistinct Orthocera like those found in the blue slate of 

 Ffernant dingle and near Bettws, Abergele, and at other localities. 



List of Fossils determined by Mr. James de Carle Sowerby, F.L.S., with the geological 

 positions assigned to the same species in the Silurian Series in Mr. Murchison's work. 



Species 1 to 4 were obtained from the red and green sandstones, e and/ of section, p. 195 ; and the remainder from 



the blue clay-slate, a. 



1. 

 2. 

 3. 



4. 



5. 



6. 



7. 



8. 



9. 

 10. 

 11. 



12. 

 13. 



14. 



15. 

 16. 

 17. 

 18. 

 19. 

 20. 

 21. 

 22. 



Terebratula nucula ... 



pulchra 



navicula 



Leptaena lata . 

 Atrypa affinis . 

 Orthis lunata ?. 



orbicularis 



Lingula ? 



Avicula retro flexa 



Nucula ovalis 



Cypricardia cymbsefor- 



mis, var 



Orthoceras striatum ... 

 annulatum ? 



inequiseptum ? 



Bellerophon trilobatus... 



Pleurotoma Lhudii ? 



Turbo corallii 



Turritella 



Euomphalus funatus .. 



Trilobites 



Crinoidal stems 



Conularia quadrisulcata 



Silurian System. 

 Ibid. 

 Ibid. 



Ibid. I 



Ibid. 



Ibid. I 



Ibid. 



Ibid. 

 Ibid. 



Ibid. 



Ibid. 



Ibid. 

 / Phillips's "» 

 \ Geol.Yorks. j 

 Silurian System. 



Ibid. 



Ibid. 



Ibid. 



Ibid. 



PI. V. f. 20. 



f. 21. 



f. 17. 



PI. III. f. 10 6 

 PI. V. f. 13. 

 PI. VI. f. 5. 

 PL Ill.f. 12. 

 PI. V. f. 15. 



f. 16. 



f. 9. 



f. 8. 



f. 6. 



f. 29. 



PI. IX. f. 5. 



Pl.XXI.f.7. 1 



PI. III. f. 16. 



PI. VIII. f 14. 



PI. V. f. 27. 



Pl.XII. f. 20. 



f. 22. 



Old Red. 



Ibid. 



Ibid. 



Ibid. 



Mountn. 

 Limestn. 

 Old Red 



Upper Ludlow 

 Ibid. 

 Ibid. 



Ibid. 



Ibid. 



Ibid. 



Ibid. 



Ibid. 

 Ibid. 



Ibid. 

 Ibid. 



Ibid. 

 Ibid. 



Aymestry Limest, 



Ibid. 

 Ibid. 

 Ibid. 

 Ibid. 



Ibid. 

 Ibid. 



Lower Ludlow. 



Ibid. 

 Ibid. 



Ibid. 



Ibid. 

 Ibid. 



Ibid. 

 Ibid. I 



to Caradoc 

 Sandstone. 



to Caradoc 

 Sandstone. 



to Caradoc 

 Sandstone. 



Wenlock 

 Limestone. 



