CELLULARIA. 339 
not its specific name from the number of the spines, but 
from having three cells betwixt every two joints. 
** Anerture superior, subterminal, oval. 
3. CELLULARIA scrupPosa, Creeping Stony Coralline, H//is. 
Hab. On the roots of Laminaria digitata, and on coral- 
lines and seaweeds. Peterhead, not uncommon, Mr. Peach. 
It is common in the Firth of Forth, and in the north of 
Scotland, but we have very seldom met with it m the west. 
Mr. Robert Gray has found it in abundance to the east of 
Dunbar. Where it is found at the roots of seaweeds, it 
often covers an inch square, creeping along the surface, and 
attaching itself by tubulous root-like fibres; the cells are 
oval; each cell has two appendages, the one in the form of 
pincers, and the other is furnished with a long moveable 
bristle. 
4, CELLULARIA REPTANS, Ld/is. 
Hab. On corallines, seaweeds, etc.; common. 
This is pretty like the preceding, but the tufts are larger. 
The branches are dichotomous; the cells have an oblique 
opening, armed with four or sometimes five short spies. 
The colour is lighter than that of the preceding; with us it 
is light grey, and not unfrequently tinged with red. It is 
very abundant, on the coast of Ayrshire, on fHalidrys sili- 
