50 CAMBRIAN. 



The following Table is intended to show the general relations 

 between the Cambrian rocks of the Lake District and those of 

 Wales. 



Wales. Lake District. 



In the Louver Cambrian rocks we meet with the first 

 definite traces of animal life, and in the oldest group of rocks 

 we find many classes represented, most important among 

 them being Brachiopoda and Crustacea. The earliest stage 

 of this group has, however, at present yielded only Anne- 

 lides ; higher up we meet with Ostracoda and Brachio- 

 poda {Lingulella, Disciiia, and Obolella), and still higher 

 a more varied fauna — species of Paradoxides, Agnostus, 

 and ConocoiypJie, among the Trilobites (Crustacea) being 

 most prevalent. Sponges, Pteropods, and Cystideans also 

 occur. Hence we must probably look to Pre-Cambrian 

 times for the origin of life. The Middle Cambrian rocks 

 introduce many forms of Graptolites, also Olenus, Parabo- 

 lina, and SpJuvi'opJithahnus^ among the Trilobites ; and 

 Kiitorgina among the Brachiopods. Phyllopods,^ Cephalo- 

 pods, 2 Lamellibranchs, Crinoids, and Asteroids, appear. 

 The Upper Cambrian (Ordovician or Lower Silurian) rocks 

 introduce Asaphus, Angelina, Cheirurus, Ainpyx, Ogygia, 



1 T. R. Jones and H. Woodward, G. Mag. 1884, pp. 348, 393. 

 ^ For descriptions and figures of Palaeozoic Cephalopoda, see Monograph of 

 British Fossil Cephalopoda, by J. F. Blake, Part I. 1872, 



