To face page 181. 

 ERRATA. 



Page 181, nine lines from bottom, and first two lines in p. 183, /or that in con- 

 sequence, &c., read neverthelesa had retained two distinct names for one natural 

 system, he would thereby have done disservice to geological science. 



Page 183, six lines from the bottom, /or synonymous, read equivalent. 



Quart. Journ. Geol. Soc. vol. viii. Part I. 



