27 
|l' e cells of the S. argenlea nevor possess the lateral teeth 
Serv ec) in the S. cupressina. The prominent tooth on the 
^ternal edge of the apertures of the latter is sometimes 
®"nd in the former; and the lateral teeth which are 
j Q " a ys absent in the S. argentoa are sometimes deficient 
j S. cupressina; and in such a case it. would be almost 
^Possible to decide to which species, such a specimen 
elpnged. Ellis says the S. cupressina grows in deep water, 
s ,"'e the other is confined to shallower water near the 
‘ lQ res. My observations are just the reverse of this; for all 
jj e specimens of the S. argenlea which I have found on 
|.^ e Cornish coast have been at from eight to ton leagues 
£, 0q > land, in about fifty fathoms water. At what depth the 
lv ’ Cll pressina grows about St. Ives I do not know, but the 
r a | er in that neighbourhood, though deep, is, I believe, 
her shallower, than of that portion of the English channel 
0, n whiah my specimens of the S. argenlea have come. 
G THUIARIA. Fleming. 
e ?eri c Character: Polypidom plant-like, rooted by tubular 
hbres, erect, dichotomously branched or pinnated ; the 
®®ils sessile, biserial, adnate to the raehis, or imbedded in 
he substance of the stein and branches; vesicles scattered; 
h°lypes hydrafortn. 
p r A he most characteristic difference between this and the 
0)) ^ Cei |ing genus, and by which it may be distinguished at 
tjj e > is that the cells are imbedded or close to the stem, and 
e a perture not everted. 
0 TTLE-BRUSH CORALLINE. Tkniaria Thvia. “Cells 
fc Vato 'elliptical, rather acute; vesicles pear shaped.” — 
°*hbald. 
f, ^“itle-brush Coralline, Ellis’ Coral., p. 10, no, 9, pi. 5, 
p ’ “ B. Sertularia Thuja, Ellis and Solander’s Zooph., 
p' Tnrton’s Lin., vol. 4, p. 678. Stewart’s Elern., vol. 2, 
^2. Lamonroux’s Cor, Flex., p. 193. Tluiiaria Thuia, 
p) s Qli . n g’s Brit. An., p. 545. Johnston’s Brit., Zooph., p. 137, 
‘ 5lv * and xv., figs. 1, and 2. 
( From deep water. Polperro. 
hak a 1601 P ercurrent > erect, filiform, rigid, zig-zag, knotted, 
tuff underneath, bearing on the upper part a cylindrical 
°f dichotomous short equal branches, corning off alter- 
aldg ^ * at *d so disposed that four complete a whirl. “Cells 
k*t>c Passed, arranged in two rows, sub-alternate, smooth, 
A ( re d from the base to a contracted orifice.” Johnston. 
q,. n §le specimen is all that has yet been obtained. 
(Ik le J'°nng of this species very much resembles the next, 
* -^rticulata), but may always be distinguished from it, 
