172 OUR COMMON BRITISH FOSSILS. 



in the Upper Silurian rocks near Kendal ; and the 

 student will find a capital collection of them in the 

 museum of that town. A more delightful neighbour- 

 hood for fossilizing than Kendal can hardly be found 

 in England, or a more varied one. I have seen 

 Serpulites more than a foot long in the deserted 

 Silurian quarries near Ledbury. 



The Secondary rocks contain true Serpula, and 

 these fossils are not without a special value to the 

 physical geologist. Some of them may be found 

 sprawling over the interiors of bivalve shells, or 

 covering the naked tests of sea-urchins in both 

 instances plainly informing us that the life-and-death 

 conditions of the ancient sea-floors were very like 

 those of our day. Moreover, the occurrence of these 

 creeping worm-tubes over the dead tests of such sea- 

 urchins as Ananchytes one of the commonest in 

 the Chalk shows us that the chalky ooze must have 

 been forming very slowly, or it would have buried up 

 the dead animals before the sea-worms had managed 

 to spread their tubes over and about them ! 



We frequently get the tubes of Serpula attached to 

 fossil bivalves in the Lias and Oolitic rocks : some- 

 times they form dense and tortuous masses, as in the 

 Oolitic marlstone near Banbury, and in the well- 

 known " Serpula-bed " at Blue Wyke Scar, near 

 Scarborough where the geologist may obtain abun- 

 dant fossils, and enjoy some of the finest coast scenery 

 in England at the same time. The tabular Iron- 



