HARD WICKE ' S S CIE NCE-GOS SIP. 



37 



wealth of Zoantharian life our modern seas are quite 

 poverty-stricken. All that even the warmer waters 

 of our Devonshire and Cornish coasts can now support 

 are a few pretty but insignificant corals, the largest 

 of which is Caryophyllia, a genus which first appeared 

 in the seas of the globe during the formation of the 

 Wenlock limestone, and has been in existence ever 

 since. Another recent British coral is the little 

 Balanophyllia regia. Both these British corals may 

 be seen in the living state in the small table tanks at 

 the Crystal Palace and Brighton Aquaria, and a 

 brief examination of them will enable the student to 

 form a good idea of how the hard calcareous substance 



Fig. 30. — Favosites polymorpha, an abundant Silurian and 

 Devonian Coral. 



Fig. 31. — Sieiiofora (or Favositcs) fibrosa, an abundant 

 Silurian Coral. 



which remains as " coral," is secreted by the investing 

 flesh. He will also be able to restore in imagination 

 the vivid and many-coloured appearance presented by 

 the sea-floors of the Palaeozoic epoch, when corals 

 were so abundant, from the tints and colours with 

 which the flesh of living coral-animals is usually 

 distinguished. 



A quieter place for fossil coral-hunting than Dudley, 

 is the neighbourhood of Wenlock, in Shropshire, 

 where that division of the Upper Silurian formation 

 called "Wenlock limestone" crops up, and whence 

 it has derived its name. No better place would be 

 found for a short tour, and fossil collecting might be 

 agreeably diversified by a little archaeology, which 



the old Norman abbey, &c, of the town would 

 afford. All the fossil corals mentioned as abundant 

 at Dudley are also to be found in the neighbourhood 

 of Wenlock, with the addition of the beautiful 

 Lonsdalia Wenlockensis. Benthall Edge, about two 

 miles distant from Wenlock, is a famous place for 

 fossils, and corals are there especially abundant, and in 

 excellent preservation. It overlooks the Severn, and 

 the busy but still picturesque Coalbrook Dale. 

 Wenlock Edge is interesting to the physical geologist, 

 for it stands up from amid the softer Wenlock shale . 

 As might be expected, the greater ease with which 

 the latter has yielded to weather action has caused 



Fig. 32. — Heliolites inter stinctvs, a common Silurian Coral. 



frj&Su- 



Fig- 33. — Portion of Heliolites interstinctus magnified, to show 

 corallites. 



it to be denuded into the plain which it now under- 

 lies. How abundant the fossil corals are in the 

 limestone here may be gathered from Professor 

 Owen's statement that " Wenlock Edge is itself a 

 coral reef thirty miles in length." Nearly all the 

 fossil Upper Silurian corals figured and described by 

 Edwards and Haine in the publications of the 

 Palaeontographical Society may be found in the 

 neighbourhood of Wenlock. There are plenty of 

 quarries about, and the student will soon find 

 abundance of materials of all kinds. 



From Wenlock, the geological wanderer can soon 

 make his way to other classic grounds, whose names 

 are famous to the reader of " Siluria." The various 

 subdivisions of the upper beds crop out over a 



