140 BRITISH MARINE ALGZ. 
frond. The culour is a dull purplish red, occasionally marked by delicate 
tints of pink, and in drying, is tinged here and there with faint shades 
of green. Although this species is a rarity, it is widely dispersed, being 
found in various situations north and south of the equator. 
The genus Gelidium, which was formerly included in the extensive Order, 
Cryptonemiacee, is now the only British representative of the newly 
arranged Order, Gelidiacee, a group of plants of a horny or cartilaginous 
substance, which are represented in one form or other in almost all seas. 
The well known Gelidiwm corneum is a most variable plant; so mu¢h so, 
indeed, that in order to characterise the numerous forms satisfactorily, 
Dr. Harvey has named and described no less than thirteen varieties, all of 
which are found in various situations around the British coasts. The 
figures of the varieties which I am about to describe are from branches 
of plants in my possession, each of which is typical of its particular variety, 
and these will help students to identify similar plants of this genus, 
the varieties I have figured being those most commonly met with. In 
Fig. 129, a represents a branch of variety flzzwosum, the fronds of which are 
from 2in. to 4in. high. The branches are long and narrow, but decreasing 
in length as they approach the summit of the stems. The branches are 
mostly opposite, spreading out widely from the stem, and sparingly set 
with short, blunt, or sometimes pointed ramuli; b is a larger branch of 
the var. pinnatum. The fronds are from 4in. to 6in. high. They are more 
copiously branched than the foregoing, and the stems are thicker, and they 
are set throughout with spreading pinne or wing-like branches, which are 
blunt at the tips; c is the pretty and very distinct var. latifolium, so 
called from its very broad flat stem and branches. The fronds are usually 
3in. or 4in. high ; the secondary branches are mostly simple, but all are set 
with short bristle-like pinnule or ramuli. In Fig. 130, d is a terminal 
branch (slightly enlarged) of var. pulchellum, the fronds of which are 
about 4in. high, capillary or hair-like: long, thin, and generally straight, the 
stems being set on each side with short pinnez, mostly of uniform length, 
tapered at their insertion, and obtuse or blunt at the tip. The spore-bearing 
tubercle of this genus is called “‘favellidium,” and this is usually elliptical 
in form, and is produced just below the tips of the ramuli, which it 
swells or bulges out, the central portion being of a deeper red than the 
rest of the pinnule. A fruited branch of a narrow form of Gelidium lati- 
folium is represented at e, Fig. 130. Most of the short ramuli on each 
side of the stem bear favellidia near the tips. Var. aculeatum, is a 
somewhat rarer plant than the foregoing, the fronds are about 2in. high, 
irregularly divided, but much branched, the lesser branches being some- 
what crowded towards the summit of the stem. All the branches have 
acute tips, and are set with short, spreading, sharp-pointed ramuli, a 
character which is constant, and is referred to in the specific name. 
A frond of this variety is represented at f, Fig. 130, enlarged about a third 
of the natural size. Two very curious and rather rare varieties are re- 
presented in Fig. 131, where g is a terminal branch of var. crinale, the natural 
7 +". 
