A very remarkable variety, wilk a stipitate frond, carlilaginous below, branched; branches or segments
oblong, wedge-shaped, inclining to palmate, strongly nerved a t the base ; the nerve ramifying over the whole
membrane, and visible to the extremity of the frond. In some specimens these segments are stipitato, and
almost resemble the leaves of a Ddesseria. Sori in marginal leaflets.—Î. serrulatum. Harv.—Frond liMar,
attennated, mnch branched, with a broad nerve at tho base, which vanishes abont the middle, the marains
sharply serrate. “
1. Rhodomenia laciniata. Grey.— Fucus laciniatus. Turn. t. 69.
2. Rhodomenia polycarpa. Grev.— Crypt, t 352.
Another specimen in the Herbarium probably belongs to this species also.
3. Rhodomenia ciliata; /3. microphylla.
A remarkable variety, with a lanceolate outline, throwing out stipitate lanceolate leaflets from its margine
and disk; these m turn are cUiato-dentate, with lanceolate compressed ciliæ, or incipient tertiary leaflets on
both surfaces.
1. Gelidium cartilagineum. Gaill.—Fucus cartilagineus. Turn. t. 124.
2. Gelidium cornicidatum. Grev.—Fucus corniculatus. Turn. t. 182.
3. Gelidiimi? lanceolatum. H a rv . M S S . Fronde plana cartilaginea bipinnata, pinnis
elongatis basì attenuatis, pinnulis lanceolatis simplicibus suboppositis.
6-8 mches high, pinnately branched, the branches (pinnae) long, simple, much attenuated a t the base and
apex; 1-2 lines broad in the middle, pinnated with foliaceous, lanceolate, mostly opposite ramuli, from 2-6
lines long. Both branches and ramuli are perfectly simple, and preserve their strictly lanceolate fi-rure
throughout. ®
1. Plocamium coccineum. Lyngh.— Twcxxs coccineus. Turn. t. 59.
1. Laurencia obtusa. Lamour Fucus obtusus. Turn. t. 21.
2. Laurencia pinnatifida. Lamour.— Tnc.v& pinnatifidus. Turn. t. 20.
1. Chondr-us mammillosus. Grev— Fucus mammillosus. Turn. t. 218.
2. Chondrus constricius. Grev.—Fucus constrictus. Turn. t. 152.
3. Chondrus vermicularis. Grev. (?)—Fucus vermicularis. Tu rn . t. 221. (?)
The specimen which I refer to this species wants the fruit, which in the Chondri is of some moment in
specific characters, but the ramification and substance ^ e e with Turner’s ligure.
1. Ptilota hypnoides. Ha rv . M S S .; jugamento compresso filiformi bipinnato, pinnis
pinnuhsque alternis, liis alternatim pinnatifidis (segmentis lanceolatis) e t ramulis foliifor-
mibus lanceolatis acutis alternantibus.
This, not excepting our own P. piumosa, is the most beautiful of the genus, and one of the most elegant
of marine plants. It is readily known by the small leajlihe ramuli, (1 line long) of a lanceolate figure, which
regularly alternate with the pinnules, a pinnule and a leaflet being always opposite each other, hut standing
alUmately on the stem. Stems bipinnate, 4^5 inches high, slender, two-edged, all the divisions alternate;
pinnules closely pinnated with lanceolate leaf-like ramuli, between each of which rises a rudimentary branchlet,
which in its turn bears also a set of similar little leaves, in au alternate series, opposite each of which is a
clavate dark red receptacle full of small grains.
2. Ptilo ta pectinata. Ha rv. M S S .; jugamento compresso filiformi subbipinnato, pinnis
pihnulisque alternis, ramulis extremis (nascentibus pectiniformibus) distichis divaricato-
multifidis.
This, too, in its young state, is distinguished like the last by a very beautiful character, a little comb-like
ramulus, inciso-serrate on its lower side, being placed opposite the insertion of each pinnule; but m older
fronds, from a frequent multiplication of this structure, nothing is visible but a confused fascicle of multifid
ramuli. Tbe pinnules, or secondary branches, are closely set with similar ramuli, alternating with each
other, and in the spaces between these are situated fructiferous multifid ramuli, which bear dense clusters
of trisporous capsules.
T rib . IV . G a s t r o c a r p e ^ .
1. IviAmapapillata, Grev Sphierococcus papillatus. A g .2 2 2 .
A fine species, and an undoubted Iridaa. Shape of I . edulis, thick, flexile, its upper half bearing elongated
papilhe in great abundance, each of which terminates in one or more umbilicated warts. These warts
contain a mass of smaU seeds, lodged in a cenfral cavity, and differ principally from regular capsules, (such
as are found in the Floridece,) by passing into the pediceles, and thence into the frond, without any percep-
table alteration in the size or shape of the subjacent cellules. The outer coating of the frond also is continued
round them without interruption, and the whole is perfectly opaque.
T rib . V, SiPHONEJE.
1. Codium tomentosum. Stackh.— Tncws tomentosus. Turn. t. 135.
T rib . V I. CerajMIEjE.
1. Ccramium obsoletum. Ag . Sp. Alg. 2. p . 145.
Parasitical on Iridea papillata.
1. Polysiphonia verticillata. Harv. M S S .; fills nanis repentibus parce ramosis; ramis
obsolete articulatis, ramulis subverticillatis simplicibus acutis incurvis multistriatis articulis
dianietro brevioribus.
A very curious and distinct little species, 1-2 inches high, with a good deal the habit of Cladostephus,
but possessing the structure and substance of Polysiphonia. Colour a deep brown.