92 HANDBOOK OF FOSSILS. 



represented in Westmoreland, Scotland, and Ireland, 

 principal subdivisions are given in the Table on p. 16. 



Their 



TRILOBITE (Asa.ph.us candatus), 

 (from the Silurian). 



Orthoceras snlannnld- 

 titm (from the Silurian) . 



5. Cambrian. Under this term, derived from the old name 

 for Wales, are included many sandstones, grits, slates and flags, 

 with here and there a limestone band. They form the greater 

 part of the western counties of Wales, where they rise to a con- 

 siderable height above the sea level. The highest hills of 

 Westmoreland and more than half of Scotland are composed of 

 beds of this age. 



The fossils, save in the limestone bands, are not easy to find, 

 but in places they are fairly abundant. Brachiopods are far 

 more numerous than the Mollusca properly so-called. Of these, 

 the genus Orthis was most abundant at about the close of this 

 period. Certain beds of this age have received the name of 

 Lingula Flags, owing this prevalence in them of the curious 

 Brachiopod Lingula so like the species now living in some of the 

 warm seas of the tropics. The Trilobites included several forms, 

 and one species (Paradoxides Davidis) attained the length of 

 nearly two feet. A few star-fish, some Hydrozoans (Graptolites), 

 and the tubes and casts of Annelides and tracks of Trilobites, 



