74 
CRYPTOGAMIA. ALGiE. Fucus. 
darker and blackish near the base ; towards the apices pale, tinged with 
yellow, and somewhat transparent, blackish when dry. Substance 
flexible and tough; in a dry state rigid and brittle. Habit thick and 
bushy, branches not unfrequently recurved and twisted. Its sub- 
cylindrical frond never channelled sufficiently distinguishes it, (even in 
the absence of its vesicles, a still stronger character) from F. canali - 
culatus. Turner. 
Filiform Bushy Fucus. This distinctly new Fucus was discovered by 
Mr. J. T. Mackay, in a small creek at the upper end of Birtebui Bay, 
near the hill of Cahil, Cunnamara, but no where else; and they are not 
attached to the rocks, but lying in vast quantities of loose balls upon the 
shore. P- E.) 
F. yesiculo'sus. Plant flat, forked, midribbed, entire at the edges: 
bladders axillary, or on the sides of the midrib : tubercles in the 
ends of the leaves. 
( Turn.Hist.8B — E. Bot. 1066. E.)— Stackh.2and 6— Vettey 1— Bast. ii. 11. 
2— Gesn. Ap. Cord. a. Schmid, ic. lign. 1. 6.— H. Ox. xv. 8. row the 
last, 5 — Clus. I. 21— Lob. Ic. 2. 225. 1— Ger.Em . 1567. 4— Park. 1293. 
11—Ger. 1378. 3. 
The bladders at the divisions of the leaf in pairs, the others solitary. Turns 
red in decay. The bladders in the substance of the leaf contain 
the fructifications. Linn. Suec. n. 1145. Plant about a foot high, thick, 
leathery. Leaves half to one inch in breadth. Bladders elliptical. 
Stackhouse. 
This plant is subject to considerable varieties, the chief of which are 
1. Bladders in pairs, axillary. F. divaricatus , Sp. PI. 
2. Bladders in pairs at the sides of the midrib, the axillary ones solitary. 
3. Bladders without any regular order. 
4. Tubercles in the terminations of the leaves. 
5. Tubercles in a short lateral leaf. 
6. Tubercles acutely oval; leaves waved at the edge. 
7. Bladders almost covering the plant; often confluent. The fruit ter¬ 
minating, and purse-shaped. Mr. Stackhouse. ( F. inflatus. Smith Icon. 
Plant. 75.—FI. Dan. 1127. E.) 
8. Branches not broader than a straw. Bladders few or none. 
9. Branches proliferous, the shoots inversely egg-shaped. 
10. Ends of the branches twisted. F. volubilis of Ray and Huds. not 
of Linn. 
All these varieties are common in our seas, excepting the first sort,which 
is mentioned by Linnaeus, but has not been identified on our coast. 
The structure of the fructifications much resembles that ofjF. serratus, and 
the mid-rib dies away where the granulations begin. 
Both this and F. serratus, when fully grown, are forced continually by 
the flux of the tides against the rocks, and by the constant collision 
lose the membranaceous part of their lower leaves, while the main stems, 
which are exceedingly tough, acquire a smooth roundish form, and the 
forked ribs which prevade the upper leaves, wear away to sharp thorny 
points. In this state both these plants have a shrub-like appearance, 
whilst the short leaves and inflated vessels at the summit of the branches 
