spreading and set with spine-like ramuli. Twdercles spherical, sessile on 
the sides of the cilia. Tetraspores contained in the cilia, oblong, transversely 
zoned. Substance cartilagmous, but flaccid, soon altermg im fresh water. 
Colour a dull red, which quickly becomes orange in fresh water, and 
changes to brownish in drying ; in which state the plant, if placed under 
pressure, adheres to paper, but shrinks considerably. 
This species, first distinguished by Micheli, received the specific 
name which it now bears from Messrs. Goodenough and Wood- 
ward, who described it in their memoir on the species of Fucus 
in the Linnean Transactions. Mr. Turner in his Synopsis, and 
subsequently in his great work, regards it as merely a variety of 
R. ciliata, to which species, no doubt, it is very closely allied. 
Mrs. Griffiths, however, clearly pomts out characters by which 
they may be distinguished, namely, the more flaccid substance 
and duller colour of #. jvdata, and the different position of the 
tetraspores, these being in the present species confined to the cilia, 
and in 2&. ciliata immersed in the lacinie of the frond. To this 
may be added that &. ci/iata is a winter plant, and R. jubata in 
perfection in summer. 
The ¢wercles of this species are rare. I have only gathered 
them in a locality at Miltown Malbay (in rock-pools opposite 
“ Billowville ”’), but in that station I found them abundantly, 
first in 1831, afterwards m 1847. The plant is common on 
most of the British shores, but scarcely ever found with tubercles. 
Few plants are more sportive in appearance. Our plate re- 
presents some of the more common forms: but specimens are 
often found in which the cilia are much more copiously developed, 
or where the whole frond is exceedingly slender, filiform, and 
entangled. Such examples may at first sight be mistaken for 
luxuriant tufts of Gigartina acicularis. 
Fig. 1. RuopyMENtIA suBATA; fronds :—of the natural size. 2. A cilium, with 
tubercle. 3. Vertical section of a tubercle. 4. Tetraspores. 5. Section 
of the frond :—all more or less magnified. 
