124, BRITISH MARINE ALG. 
curious production was formerly included in the Oorallinacew; but its 
structure, which is more of a leathery than a stony nature, has caused 
it to be removed from the calcareous order of marine alge, and associated 
with a small group of singular plants, which, like itself, are either circular 
or irregularly shaped patches of a red or brownish-red colour, which are 
found on stones and shells, or attached by means of minute fibres on their 
under sides to the surfaces of rocks. The order Squamariew has been 
formed for their reception. In addition to the species just described, I 
will merely mention the names of the others, since they possess very 
little interest for the ordinary collector. They are as follows: Peyssonelia 
Dubyt, Petrocelis cruenta, Cruoria pellita, and Cruoria adherens. 
The Order Spherococcoidee, so named from the roundish form of the 
fruit, is an assemblage of seaweeds, of a rosy or blood-red colour, some of 
which are leafy, others consist of broad, expanding, cleft, or laciniated 
membranes, and some few are filiform, and more or less branched. At the 
head of this Order stands the genus Delesseria, named in honour of 
M. Delessert, a French botanist; and here I must express my regret that. 
the charming plant, which until recently was known as Delesseria sanguinea, 
has been removed, not only from this genus, but has been placed in 
another Order, ‘‘a measure,” writes Dr.‘ Harvey, ‘‘ rendered necessary 
by the new principles of arrangement developed by Professor Agardh,” 
whose system is now generally adopted by algologists. In outward 
appearance, and even in the internal structure of its stem and leaves, this 
fine species is a true Delesseria, but the structure of its fruit being very 
different from that of the Sphwrococcoidee, it has very properly been 
transferred to the Order Rhodymeniacee, and is now known as Maugeria 
sanguinea, @ name which was given to it by S. O. Gray, Esq., in his 
work on “ British Seaweeds,’ published in 1867. However, for the con- 
venience of those who have been accustomed to regard this plant as Deles- 
seria sanguinea, I will figure and describe it before I pass on to a de- 
scription of the beautiful leafy plants now included in the genus Delesseria. 
Maugeiia sanguinea, represented at Fig. 114, is one of the most striking 
and beautiful of all the British red seaweeds. In its perfect summer state 
when grown in favourable situations in deep water, the fronds are from 
Gin. to 8in. or 10in. long, and from 2in. to 6in. wide; each leafy expansion 
has a short stalk and a distinct midrib with veins on each side, the margin 
of the membranous leaves being entire, and often beautifully waved, so 
that when fully grown plants are mounted on paper, they present the most 
beautiful variety of pink and deep red tints, owing to the folding over of 
the delicate membranous margins. Occasionally in proliferous specimens, 
long narrow leaflets are thrown out from the midrib of the primary 
leaves. Small but beautiful forms of this leafy plant are found sometimes 
in shady rock pools, but always submerged, and mostly under the shelter of 
the larger olive weeds. The winter state of this plant is very different to 
its summer condition. All the delicate wavy margin disappears, and from 
each side of the midrib springs a series of ovate leaflets (sporophylla), in 
