64 



rarPLE-MARKS, BONE-BEDS, etc. 



TJppeii 



Gallery. 



surface of which the ripple marks run transversely to each 



other. 



Wall-case 41. ganshire. 



Penarch, 4 miles South of Cardiff, 



182. — Small ripple marks on Old Red Sandstone. 

 183.— Ripple marks on white beds of the New Red 

 Sandstone. — Cubing ton, near Leamington, Warwickshire. 

 184. — Sandy limestone with surface markings from th 



e 



"Horseflesh" beds of the middle Parbech, near the fifth mile 

 stone, on the east side of the road to Bridport. — Upivey, 

 Dorset. 



185. 



Lias bone bed with surface markings. Westbury. 



on- Sever?i, Gloucestershire. 



186 # — Deep ripple marks on Old Red Sandstone. 



187. — Purbeck limestone with fucoidal markings, from 

 the limekiln quarry. 



Kingston, Dorset. 

 188. — Keuper sandstone, exhibiting in relief the cracked 



markings of a dried surface. 



Neivent 



189 and 190. — Lias bone bed, (see Nos. 171, 181, and 



185). 



Westbury -on- Severn, Gloucestershire. 



•Lower Llandovery rock with fucoidal markings. 



191. 



•Aberysttvith, Cardiganshire. 



Wall-case &&. 



Flint, Chert, and other Siliceous Bodies, contained in 



rocks of various kinds. 



Arranged and described by H. W. Bristow. 



A large part of the specimens in this case are chalk flints. 

 These generally occur in layers, chiefly in the upper part of 

 the chalk. It has been proved by Mr. Bowerbank that 

 in almost all cases they are silicified sponges. This remark 

 also applies to many other flinty and cherty bodies which 

 occur in the lines of bedding of oolitic and other limestone 



rocks. The external forms of these bodies are often them- 



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Mm 



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