(3) 
which lived in ages that have long since passed away. 
Yet such is the undoubted fact; and, to. be informed 
of this circumstance, I flatter myself, will not lessen 
that pleasure which they might otherwise receive from 
an excursion to this part of our Island. 
- Without some such information, many of the most 
curious pheenomena in nature might remain con- 
cealed; and various hidden, but highly interesting 
circumstances, would often escape the observation of 
the generality of travellers: nay, it requires diligence 
and acuteness, even in the experienced and most in- 
quisitive, sometimes to discover them, and to satisfy 
the mind of their actual existence. Nor is it by a 
hasty view alone, during a short visit of a few days, 
but by frequent and repeated examinations, that the 
peculiar features of any district can be satisfactorily 
traced or explained. 
I am well aware that some highly respectable cha- 
racters, men more competent to the task, have already 
given occasional and unconnected remarks on the 
Plymouth Limestone; but the result of these remarks, 
whether from want of time and opportunity, or per- 
