252 



HA RD WICKE 'S S CIENCE - GOSSIP. 



employment of laying open, layer after layer, like the 

 pages of a book, the thin laminae of the shale blocks 

 he is working upon. They are verily written ' ' within 

 and without," and the iron sulphite into which nearly 

 all the organic remains of these beds have been con- 

 verted, looks as if they had been electrotyped on the 

 surfaces of the black shales. 



Fig. i86. K&a.A oi Ichthyo- 

 crinns, an American Silu- 

 rian genus of Crinoids. 



Fig. 187. Head o{ Eucalypto- 

 cn'inis, a De^■onian Encri- 

 nite. 



Fig. 188. Actiiwcriinis 

 trincoittadactylns, a' 

 Carboniferous genus. 



Fig. 1S9. Head of 

 Taxocri/uts 

 (Devonian). 



of natural casts, nobody will deny their abundance 

 or beauty. We have here seen slabs of si.\ feet in 

 length completely crowded with these Encrinites, roots, 

 stems, and heads, just as they grew, looking to all the 

 world like a fossil tulip-bed ! 



Again, what geological student who has made a 

 pilgrimage through the Peak district of Derbyshire, 

 has not had his attention called to the ' ' Encrinital 



Al Bradford, near Bath, we have numerous 

 Encrinites occurring in clayey rocks, instead of in 

 limestone, their usual storehouse. This clay (60 feet 

 thick) is in the Oolitic formation, and proves exactly 

 the same conclusion as we have drawn from the En- 

 crinites buried in the Primary rocks, namely that muddy 

 sediments always kill them off and bury them where 

 they are. In the hard slates (formerly shales) of the 

 Upper Silurian formation, about a couple of miles from 

 Llangollen, in North Wales, the student may find some 

 beautiful specimens of the characteristic Upper Silu- 

 rian Encrinite known v& Actitwcriniis pttlchcr. Well 

 does it deserve its specific name, for no Encrinite 

 exceeds it in gracefulness of shape. At the slate 

 quarries visible on the hill side, as the reader walks 

 towards Val Crucis Abbey, he may see abundance 

 of these fossil Encrinites, and although all the structure 

 of the fossils has been completely altered since they 

 were alive, and they are now really in the condition 



Fig. 191. Flatycrinus tyi^hi' 

 tidactyhiS (carb. limestone). 



Fig. 192. Head oi Ac- 



tinocrimts cuspidatiis 



(carb. limestone). 



Fig. 190. Clyptocritiiis (Silurian). 



Fig, 193. Head of 

 Rhodocrinns. 



Fig. 194. Lower part of stem 

 of Encrinite, showing mode 

 of attachment to sea-bottom. 



Fig. 195. Cufrcssocrbncs. 



limestone," as everybody calls the rock, which is sO' 

 completely filled or rather made up of Encrinite stems 

 that wesometimes find nothingelse ? "Screw Stones," 

 the county folk call them — that name being given in 

 reality to those siliceous casts of Encrinital stems 

 which occur abundantly in the Chert bands, where 

 the original limy matter of the ossicles (as the indivi- 

 dual joints of the stems are called) has been dissolved. 



