198 OUR COMMON BRUTISH FOSSILS. 



about four miles from Llangollen, among the moun- 

 tains, we find abundance of fossils, and among them 

 are various species of Pkacops, Calymene, etc. The 

 pretty village of Woodhope, near Hereford, is another 

 charming collecting-ground, rich in Upper Silurian 

 fossils ; and here we find Illczmis, Homalonotns, 

 Phacops, etc. Trilobites are also abundant in the 

 Wenlbck shales forming part of the Malvern Hills. 

 Of the Dudley limestone and its treasury of these 

 peculiar ancient forms of life, I have already spoken. 

 The neighbourhood of Ludlow has also long been 

 known as a rich storehouse of Trilobites of various 

 species and genera. 



In the Devonian beds it is only here and there we 

 can meet with Trilobites in any abundance. One of 

 the best localities is Newton Abbot, in Devonshire, 

 where the limestone contains numerous Trilobites. 

 The Pilton beds yield certain species of Phacops in 

 plenty. The Trilobites are most abundant in the 

 Middle Devonian strata of England, owing to the 

 probable fresh-water conditions under which most of 

 the other beds 'were deposited. The Carboniferous 

 limestone, both of England and Ireland, is frequently 

 rich in Trilobites of the genera Phillipsia and Grif- 

 fithsides, named after two distinguished geologists. 

 At Castleton, in the Peak of Derbyshire, along the 

 outcrop of the strata forming Tre-cliff, is a band 

 especially crowded with Phillipsia; and in the 

 curious gorge to the immediate south of the cavern 



