ULYA ATOMARIA. CONCENTRIC-DOTTED ULYA.
ULVA atomaria, fronde olivaceo-flavèscente, plana, enervi, membranacea, cuneiformi, palmata; segmentas
lineari-cuneiformibus, subramosis, margine subciliatis ; seminibus in lineas curvatas trans-
• versales dispositis.
ULVA atomaria. Woodward in Act. Soc. Linn. vol. 3. p . 53. Engl. Bot. £.419-
FUCUS zonalis. Lamouroux,'Diss. Fuc.p. 38. t. 2,5. f . 1.
FUCUS pseudo-ciliatus. Lamouroux, Diss. Fuc.p. 41. £. 25. f . 2.
ULVA serrata. Lamarck Fl. Fr. ed. 3. vo l. 2. p. 11. Lam. FI. Gall. Syn: p. 3. Lam. Diet. vol. 8.
p. 166.
DICTYOTA zonata. Lamouroux in Journ. de Bot. vol. 2. p. 40. Id. in Annales du Mus. d’Hist.
N at. vol. 20. p. 9,72. ' P oiret in Lam. Diet. Suppl, vol. 2'. p. 477.
D IC TY O TA ciliata. Lamouroux in Journ. de Bot. vol. 2. p. 41. Id . in Annales du Mus. J Hist.
N at. vol. 20. p. 273. ■ Poiret in Encycl. Meth. Suppl, vol. 2. p. 477.
C lass a n d Ord e r . CRYPTOGAMIA ALGJE.
[N atural Or d e r . ALGiE, Juss. Decandollei]
Ge n . Char. Frons membranacea seu gelatinosa. Fructijkatio (si adsit) per totam frondem quaquaversim
sparsa. (JVoodw. in Linn. Trans, vol. 3. p . 48.)
Radix callus, exiguus, explanatus, tomento fusco, denso,
e fibris articulatis, intertextis composito, ubique
vestitus.
Frondes ex eadem radice plurim®, plan®, enerves, e
basi angusta sensim dilatata ut unicuique figura
plus'minus cuneiformis sit, late in his, in illis ad
linearem potius accedens, et in quibusdam pro-
pemodum linearis; longitudo, qu® plerumque
vix sex pollices ®quat, interdum pedem superat;
' ömnes ad uniüs alteriusve pollicis altitudinem
indivis® assurgunt, mox laciniis numero, situ la-
titudineque pariter incertis, pa'lmatim ramos®
fiunt, qu® etiam lacini® nunc totius instar fron-
dis sunt cuneiformes atque iterum iterumque pal-
mat®, nunc lineares et subdichotom® aut indivi-
s® 5 apices enormiter fissi, segmentis, nisi fallor,
in illsesis, obtusis, truncatis, quod tarnen visu est
perrarum; et s®pissime acuta, quod casu accidit,
reperiuntur : margines in his integerrimi, in illis
ciliato-dentati; ciliis exiguis, sparsis. Substantia
membranacea, tenerrima, ita tarnen ut frondis
pars inferior- reliqua sit fi'imior et quodammodo
ad cartilagineam accedat: color dilute olivaceo-
Tüscus, flayoperfusus, diaphanus.
FrüCTIFICATIO: semina exigua, subrotunda, atro-fusca,
limbo lato, pellucido cincta, in fascias disposita
intervallo vix duarum linearum spatio sejunctas,
' concenfcricas, qu® singul® e duplici seminum
serie constant.: neque h® fasci®, qu® totam frondem,
excepto juxta basin, transversalim percur-
runt, adamussim sunt fact®, sed plus minusve
sunt interrupt®, conspiGiuntürque semina alia
sparsa.
Root callous, small, expanded, entirely covered with a
brown downy substance, which is composed of'
jointed and much entangled fibres.
Fronds many from the same root, plane, nerveless, from
a narrow base gradually dilated, so that to each
there is a figure more or less cuneiform, in some
•widely so, in others approaching to linear, and
even altogether linear; the length, which is generally
about six inches, sometimes exceeds a foot;
all of them, to the height of one or more inches,
arise undivided, then they become branched in a
palmated manner, with lacini® varying in number,
situation and width, which lacini® sometimes,
like the whole frond, are wedge-shaped
and again and again palmate, sometimes linear
and subdichotomous or undivided : the apices irregularly
cleft, with segments, in the uninjured
specimens, if I am not deceived, obtuse and truncate,
in this state, however, they are rarely seen:
most frequently they are found acute, which is
caused by accident: the margins in some are entire,
in others ciliato-dentate, having the cilia
small and scattered. The substance is membranaceous,
very tender, but the lower part of the
frond is firmer than the rest and approaches to
cartilaginous: the colour is a pale olivaceous
brown, tinged with yellow, diaphanous.
Fructification : small, roundish, black-brown seeds,
surrounded by a wide péllucid limb: these are
disposed in bands, scarcely two lines distant from
each other, concentric, each of w-hich consists of
a double row of seeds; nor are these bands, which
run transversely across the whole of the frond,
placed with great regularity, but are more or less
interrupted, and scattered seeds are discoverable.
Fio\ 1. Segment of the Frond to show its reticulated structure. Fig. 2. Seeds—both magnified.
Originally found among the rejectamenta of the sea upon the beach a t Yarmouth by Mr. Lilly Wigg : since
gathered in a growing state by Mr. Turner at Cromer and Sheringham in the same, county ; and a t Brighton by
Mr. Borrer ; and by Mr Dillwyn in the pools among the rocks about the Worms Head, Glamorganshire.
This Ulva, one of the most conspicuous in point of beauty, and from its size not likely to be passed over, appears
nevertheless to have escaped the notice of botanists till a description of it was in 1794 furnished to the Lin-
næan Society by Mr. Woodward, to whom every part of the English Flora, and particularly that which treats of
the submerged Ah'ce, is under such lasting obligations. On the Norfolk and Suffolk coasts it is by no means of
rare occurrence, but is principally confined, like some others of the annual species, to the months of July, August
and September. We have also seen in the herbarium of Sir James Smith, specimens from Ceylon. M. Decandolle
in the Flore Française, represents it as a native of the coast of Normandy ; and M. Lamouroux, of Rousillon, Catalonia
and S t. Domingo. This latter naturalist, in his Dissertations sur plusieurs Espèces de Fucus, above referred to,
was led to describe and figure the more narrow and the broader varieties, the latter entire a t its margin, the former
ciliated, as distinct species. The same division he has followed in his Mémoire sur les Genres des Thalassiophytes,
recently published by the French Institute, as well as in another mèmoir recorded in the Journal de Botanique, in
which latter work he refers to his figure of F. pseudo-ciliatus as belonging to the English U. atomaria ; but every
naturalist at all acquainted with this tribe of vegetables will far more easily recognise that species in his F. zonalis.
This latter is indeed a good representation of it ; the other shows it only in an injured and imperfect state. This
we are particularly induced to notice, for the sake of the other French botanists, whom we apprehend to be
likely to be led into error on the subject.
The figure of Ulva atomaria in English Botany, which is excellent, is admirably adapted to include both
M. Lamouroux’s species. The genus Dictyota, subsequently established by this botanist, we agree with him in
considering one of the most natural of the divisions of the marine Alga, though we doubt whether a great proportion
of°the plants which he makes it to include can be retained with it. For this reason, and because we are unwilling
to commit ourselves rashly on a subject that requires the most careful investigation, we hesitate a t present
about its adoption.