ii6 OUR COMMON BRITISH FOSSILS. 



Encrlnltes which sometimes for scores, if not hundreds, 

 of square miles together, covered the ancient sea-beds. 

 In the clay bands often intercalated in the Silurian 

 and other limestones, we have frequent geological 

 evidence of how large numbers of young Encrinites 

 were killed by the muddied water, and eventually 

 buried in the muddy sediments which had first 

 destroyed them. The same is often true of the fine 

 clayey shales of the Yoredale beds of Lancashire and 

 Yorkshire, where entire specimens, stems, heads, and 

 fingers, of frail but lengthy-stalked Encrinites are to 

 be disentombed in the most perfect condition. The 

 best place I know of, where these encrinital remains 

 are to be found in the Yoredale series, may easily be 

 discovered by following the bed of the river from 

 Hebden Bridge, in Yorkshire, towards High Green 

 Wood. The Yoredale shales crop out in cleanly cut 

 sections, owing to the river frequently denuding them 

 along the lines of natural joints. The geological 

 student will there find strewn about, huge cubical 

 blocks of thin dark shale, crowded with fossils, such 

 as Goniatites, Orthoceratites, Nautili, and encrinital 

 remains. He can while away many a pleasant hour 

 in these secluded but exceedingly picturesque places, 

 with the murmur of the stream in his ears, and the 

 most picturesque hilly scenery ready to greet his 

 eyes, whenever he thinks proper to turn them away 

 from the absorbing employment of laying open, layer 

 after layer, like the pages of a book, the thin lamin3e 



