INTRODUCTION. XVII 
^ovations, effected posterior to their formation. 
experience derived from observations made 
? n the Cornish Coast, can of course be but of 
httle value, either as contradictory or confirma- 
j° r y of such an opinion; yet it is proper to state 
."at Zoophytes of all the orders to be described 
the following pages have been procured from 
jy J out sixty fathoms water. Though they, there- 
" r e, may not extend to any great depth, yet 
" e y are certainly not confined to thirty fathoms 
Water as has been supposed. Algae, however, 
"i'e never found on the stones drawn from more 
"an twenty five fathoms, on any part of our 
c "ast. 
In the following pages the term polypidom is 
Ver y frequently used, but it is synonimous with 
P°lypi er 0 f continental Naturalists, and as only 
convenient mode of expression for the solid 
j| ar ts of Zoophytes, such for instance as the 
" r oy parts of Serlulariee and the solid axis of 
° r gonia; beside this, no terms are used, which 
6( loire any explanation. 
