254 OUR COMMON BRITISH FOSSILS. 



fossilizing may be had — bones, teeth, and spines of 

 fish, saurians, etc., as well as fossil shells being abun- 

 dant. It is in this formation (a part of which was 

 formerly known as the " White Lias ") that the well- 

 known but curious " Landscape marble " occurs at 

 Gotham. Practically, we may say that the Rha:;tic 

 series extends diagonally across England, from Red- 

 car, on the north Yorkshire coast, to Lyme Regis. In 

 many places its beds have been exposed, as near 

 Leicester, where shells may be got. Somersetshire, 

 however, is perhaps the best county for specimens, 

 those obtained from near Watchet having found their 

 way into most collections. Among other localities 

 where Rhaetic fossils can be hammered out are Queen 

 Camel, near Yeovil, Westbury, Purlton, Shepton 

 Mallet, Wedmore, and Beer Crocombe. 



The strata of the Lias frequently teem with fine 

 and well-preserved specimens of fossil mollusca, so 

 that it is both difficult and tedious to enumerate 

 localities for finding them, either in this formation 

 or the Oolite, of which the Lias is now usually re- 

 garded as the lowest member. A good many modern 

 genera of mollusca first make their appearance here, 

 such as Cordis, Astarte, Limncea, LitJiodomiis, and 

 Teredo. The last two are curious on account of their 

 habits, Lithodomus being a burrower, and Teredo 

 (the genus of modern "ship-worms") a borer into 

 wood, etc. 



In the Oolite proper the now widespread genus 



