52 VESTIGES OF THE 



quarried for domestic purposes. If we ovei-look the 

 dubious statements respecting Sutherland and Bohemia, 

 we have in this " system " the first appearances of life 

 upon our planet. The animal remains are chiefly con- 

 fined to the slate beds, those named from Bala, in Wales, 

 being the most prolific. Zoo2)kyta, jyohjinaria, cri7ioidea, 

 conchifera, and Crustacea* are the orders of the animal 

 kingdom thus found in the earliest of earth's sepulchres. 

 The orders are distinguished, without difliculty, from the 

 general characters of the creatures whose remains are 

 found ; but it is only in this general character that they 

 bear a resemblance to any creatures now existing. When 

 we come to consider specific characters, we see that a 

 difiierence exists — that,, in short, the species and even 

 genera are no longer represented upon earth. More than 

 this, it will be found that the earliest species compara- 

 tively soon gave place to others, and that they are not 

 represented even in the next higher group of rocks. 

 One important remark has been made, that a compara- 

 tively small variety of species is found in the older rocks, 

 although of some particular ones the remains are very 

 abundant ; as, for instance, of a species of asaphus, which 

 is found between the lamina3 of some of the slate rocks of 

 Wales, and the corresponding rocks of Normandy and 

 Germany, in enormous quantities. 



Ascending to the next group of rocks, we find the 

 traces of life become moi-e abundant, the number of 

 species extended, and important additions made in certain 



* In iJie Cumbi'ian limestone occur " calamopora?, litliodendra, 

 cyathopli_ylla, and orbicula." — Phillips. The asapliusand trinucleus 

 (cnistacea) have been found respectively in the slate rocks of Wales, 

 and tlie h'mcstone beds of the i^rauwacke group in Bohemia. That 

 fragments of crinoidea, thougli of no determinate species, occur in this 

 system, we have the authority of Mr. Murchison. — Silurian Syatcm, 

 p. 710. 



