74 BRITISH MARINE ALG. 
Some of the Sphacelariew, too, are alike plentiful in the north and south 
of this country. Sphacelaria filicina, one of the most delicate and beautiful 
of the filamentous melanosperms, is found on the north and south coast | 
of Devon, in the Channel Islands, and in the Mediterranean; and, in 
fact, there are no continental generic forms of this order known (as 
observed by Dr. Harvey) which are not represented in our marine flora. 
None of the plants of this order are gelatinous ; on the contrary, many 
of them are rigid and adhere very imperfectly to paper. This is especi- 
ally the case with the genera Cladostephus and Sphacelaria, but all the 
others are very manageable, and may be pressed so flat and close to the 
surface of the paper, as to present the appearance of the most exquisite 
engravings, rather than copiously branched and jointed vegetable produc- 
tions. 
The genus Cladostephus is represented on our shores by two common 
and very easily-recognised species. C. verticillatus (Fig. 76) is found in 
rock pools, on corallines, or growing in exposed situations, often in large 
bushy tufts from 3in. to 10in. high, the stems and branches of which are 
stiff and wiry, and are set throughout at close and regular intervals with 
whorls of little ramuli (b), all of which are incurved near the tips. These 
whorled branchlets are furnished irregularly with one or two shorter 
ramuli, which point outwards and upwards, forming, in fact, a series of little . 
crowns, whence the name of the genus, that of Cladostephus, or ‘‘ branch 
of crowns,” and the regularity with which these crowns or whorls are set 
on the branches is expressed in the specific name of verticillatus. In 
winter these verticillate tufts fall off, and another irregularly disposed 
set of ramuli shoot forth, on the outward and upper side of which little - 
elliptical spores are produced,seated on pedicels or short stalks. C. spon- 
giosus, so called from the thick or spongy nature of the branches, which 
are very densely crowded with closely-set whorled ramuli, is common on 
most rocky shores. In some situations, where the tide leaves: bare flat 
open spaces and overhanging ledges of rocks near low-water mark, this 
plant is often found in great abundance, spreading over the surface, or 
hanging from crevices in the rocks like large masses of black worsted. 
It is extremely difficult to display well on paper, and is by no means 
an attractive book specimen. The fruit is produced during winter in a_ 
similar manner to that of the preceding species. 
The genus Sphacelaria, from the Greek for gangrene, in referenee to the 
withered or decayed tips of the fruitful branches, contains several very 
beautiful plants ; some are of large size, and others are strictly microscopic. 
They are all distinguished by the extreme rigidity of their stems and 
branches, several species being of exquisite symmetry, simulating the form 
and ramification of the most delicate exotic ferns. This is especially the 
case with regard to the species Sphacelaria filicma, branches of which are 
represented at Fig. 77. This charming plant is generally considered to 
be one of the most beautiful of the British marine algw. The plant 
represented in the illustration was taken near Ilfracombe, but this species 
