8 FUCI. 
‘Fuci. b. Without leaves ; stem and branches without con- 
==" tractions ; as F. confervoides, (Turn. t. 84.) purpuras- 
pe of cens (t. 9.) and plicatus (t. 180.) of our shores. 
eens: c. With evident contractions, as F. kaliformis, (Turn. 
Front  t. 29.), articulatus (t. 106.), and opuntia (t. 107.) ofthe 
DEX. British shores. : 
10. Plocamium: “ Tubercles somewhat like grape- 
stones; stems and branches compressed, the extremities 
partitioned, or divided by septa.”—The plants of this 
genus approach nearest to thetruly, articulated sea-weeds 
or marine conferve. They are all annual ; and ‘many 
of them parasitical on the perennial species. The ele- 
gant F. plumosus of our shores belongs to this genus ; 
and the dissepiments in the extreme branches, or pin- 
nz, are beautifully delineated by Mr Turner, (Hist. 
Fuc. t. 60.) It must, however, be remarked, that 
though this new genus is evidently named from F. plo- 
camium of Gmelin (F. coccineus of Hudsonand others) ; 
yet this species, instead of affording a characteristic ex- 
ample of the genus, exhibits no traces of dissepiments in 
its branchlets. 
11, Champia: “ Capsules numerous, somewhat egg- 
shaped ; situated in papille rising from the stem and 
branches.”—This consists only of one species, a native 
of the shores of the Cape of Good Hope. 
The third order, Dictvotea, is distinguished by the 
“organization being reticulated and foliaceous; the 
colour greenish, and not liable to become black on ex- 
posure to the air.” This family consists of four gene- 
xa, Amansia, Dictyopteris, Dictyota, and Flabellaria, 
all of them well characterized by the reticulated organi- 
zation, which is visible with a common lens, or even by 
the naked eye. The fructifications are numerous, co- 
vering the surface of the leaves, on which they occur in 
groups of various shapes. The root consists of a fibrous 
callosity, furnished with very fine long whitish hairs, 
which become yellowish or brown in drying. In some 
species these hairs extend up ‘the stem, or are continued 
on one side of the frond. They increase in number 
with the age of the plant. . They seem analogous to the 
tufts observable on F. serratus, vesiculosus, and natans, 
and are probably secreting and absorbing organs. The 
dictyoteze, which have nerves or midribs, are perennial, 
and are found chiefly in equatorial latitudes : those des- 
titute of nerves are annual, and found chiefly in the 
northern seas. 
1. Amansia: “ Reticulations hexagonal, regular and 
elongated, with the points acute.”"—The species are 
foreign. 
2. Dictyopteris: ‘ Capsules forming masses slightly 
elevated ; scattered over the leaves, which are divided 
by a single nerve.”—All the species are natives of warm 
climates. 
3. Dictyota: ‘ Capsules collected in masses, form- 
ing lines having various directions.”—This is divided 
into two sections: a. Padina, with the fructification in 
transverse, incurvated, and concentric lines: b. Dicty- 
ota proper, with the fructification in longitudinal lines, 
rarely transverse and never concentric, often entirely 
or partially scattered. “The padina are analogous to the 
fuci-corallini of Gmelin, and include those species which 
the late M. Draparnaud proposed to associate as a ge- 
hus, under the title of Zonaria. 
4, Flabellaria: “ Fructification unknown ; reticula- 
tions very fine and intermixed, so as to produce an ap- 
pearance of felt."—-This includes only one species, 
found in the Mediterranean. 
The fourth order, Utvacex, is distinguished by the 
“ organization being herbaceous and uniform, the ¢c- 
1 
Plocamium. 
*Champia. 
3, Dicry- 
OTE. 
Acmansia. 
Dictyopte- 
ris. 
Dictyota, 
¥ labellaria, 
4, Utva- 
CEA, 
lour green, becoming yellowish or whitish in drying.’ Fuck 
—This order comprises four genera, a Pe 
Ulva, Bryopsis, and Caulerpa. It in most of | ethod of 
the species of the genus Ulva of Linnzus and others: youx. 
The organization resembles that of the seminal leaves Utvacrz 
of many land plants, a herbaceous tissue destitute of 
fibres and vessels. The plants of this order abound 
with a mucilaginous matter, in which the colouri 
principle sao Bes mg = the be omasenge Is 
not yet accurately known, It 1s appa very sim~ 
ple, fates to consist of naked seeds sesbelicealson the 
trond at its surface. The bodies which have been taken 
for seeds, however, may in reality prove to be capsules, | 
containing granules or seeds. Jit bet 
1. Asperococcus: “ Seeds solitary, scattered, at first Asperococ 
innate, but afterwards prominent ; stems fistular.”—Of cus. 
this genus, Ulva rugosa, Lin, may be considered as an 
example. 
2. Ulia: “ Seeds solitary, innate in the substance of Ulva 
the plant, scattered, never prominent.”—This genus is 
divided into two sections : ; 
a. With flat leaves; as U. lactuca, latissima, umbili- 
calis, all very common on our shores. ' 
6. With fistular leaves ; as U. com which co« 
vers with its fine green colour almost all rocks where 
brackish water occurs, erate ‘ 
8. Bryopsis: “ Seeds globular, nm, contained in Bryopsis. 
the prt i the branches, which PA ete fistular.”— 7% 
All the species are foreign, , nS 
4. Caulerpa: “ Fructification unknown ; stem cylin- Caulerp.. 
drical, horizontal, creeping, and branched.”—This is a 
curious genus, first described and figured in the French 
Annals of Botany for 1811, by M. Lamouroux. It is 
not clearly ascertained whether some, or perhaps everi 
all the species, should not rather be consid as be- 
longing to the animal than to the vegetable kingdom. 
The organization certainly differs from that of marine 
plants in general, and is more analogous to that of some 
zoophytes. Weber and Mohr rightly remark, that the 
stiff straw-coloured stem of a caulerpa exhibits few traces 
of vegetable organization. Even with the aid of a mi- 
croscope, neither fibres nor reticulations can be detect- 
ed ; an epidermis is observable, and a cellular. tissue, 
the cells of which are so extremely minute, that it is 
impossible to determine their form. The caulerpe are 
destitute of any gelatinous or viscid property. Their 
membranaceous substance, and: their uniformly green 
colour, have induced Lamouroux to place them among 
the Ulvaceze. Sometimes the leaves of a particular spe- 
cies, Caulerpa prolifera, are partly covered with small 
opake points; such leaves have not the brilliancy nor half 
the transparency of the others ; they are of a dull earthy 
green colour. If these points prove to be seed-vessels, 
then is Caulerpa properly placed among the Ulvacee ; 
but the fructification is at present completely unknown. 
The roots are entirely fibrous, like those of many of the 
flexible zoophytes. The Caulerpe grow, not on rocks, 
but on sandy shores, generally near high water mark, 
creeping in the loose sand and soil; and no other sea- 
weeds possess a similar mode of attachment. Viewed 
as plants, they may be considered (as formerly stated) 
as connecting sea-weeds with the vegetables of the 
earth. All the species are foreign, most of them tropi- 
cal. When fresh, they are of a fine grass greet colour, 
which is liable to to a transparent horny white. 
Several of them are ed by Turner, under the 
names of F. pinnatus, taxifolius, clavifer, (Hist. Fuc. t. 
53, 54, 57) ; and he has added some, entirely unknown 
to Lamouroux. Among these may be mentioned, 
