ition external forms, which are so invariable and definit 
bi — orders of animal life, and search into the minute 
Saath 
PROUT—BRYOZOA, 4TH SERIES. 575 
bands or wrinkles more or less concentric, sometimes inter- 
current or contorted, which are crossed at right angles by 
ces and radiating to an actual or imaginary centre, al- 
e have been induced from the considerations which fol- 
low, to separate this genus from the Ceriopora of Goldfuss. 
This genus, though well defined by its author, was rendered 
by its terms too comprehensive, and embraced within its lim- 
rately and alone, as an adequate basis for generic distinction; 
for it is well known that the superposition of layer upon 
: result of age, and we have observed sever- 
1 times in our investigations, that the expanding and en- 
from 
: 32 
