- Ser. RHODOSPERME. Fam. Ceramiee. 
Puate CLXXXVIII. 
CALLITHAMNION TETRICUM, 4. 
Gen. Cuar. Frond rosy or brownish red, filamentous; stem either opake 
and cellular, or translucent and jointed ; branches jointed, one-tubed, 
mostly pinnate (rarely dichotomous or irregular); dissepiments hyalme. 
Fruit of two kinds, on distinct plants; 1, external tetraspores, scat- 
tered along the ultimate branchlets, or borne on litle pedicels; 2, 
roundish or lobed, berry-like receptacles (favel/@) seated on the main 
branches, and containing numerous, angular spores. CALLITHAMNION 
(Lyngb.), from xados, beautiful, and @apnor, a little shrub. 
CALLITHAMNION fetricum; rigid, shrubby; stem and branches robust, 
densely covered with ramuli, shaggy below, plumulate above; plu- 
mules crowded, quadrifarious, simply pinnate ; pinnz acute, tapering 
to the base, erecto-patent ; articulations twice or thrice as long as 
broad ; tetraspores elliptical, minute, sessile on short lateral processes 
of the pinne. 
CALLITHAMNION tetricum, 4g. Sp. Alg. vol.ii. p.179. Harv. in Hook. Br. 
Fi. vol. ii. p. 342. Harv. in Mack. Fl. Hib. part 3. p. 214. Hare. Man. 
p- 108. Wyatt, Alg. Danm. no. 141. Endl. 3rd Suppl. p. 34. 
PHLEBOTHAMNION tetricum, Kiitz. Phyc. Gen. p. 374. 
ConFERVA tetrica, Dillw.t.81. EH. Bot. t. 1915. 
Has. On the perpendicular faces of rocks within tide marks, from half-tide 
level to low-water mark. Perennial. Summer. Common on the 
shores of the south of England and south and west of Ireland; less 
frequent on the east coast. Lambay, M/7. Me Calla. Channel Islands. 
Grocer. Distr. Northern coasts of France, common. 
Descr. Root, a large disc, densely covered with interwoven fibres. Fronds two to 
eight inches long, or more, tufted, fruticose ; stems as thick, or twice as thick 
as pack-thread, much branched, the branches long, and either simple or again 
divided, alternate, spreading on all sides, and densely clothed with shaggy 
or hair-like, coarse, irregularly divided ramuli, so that the divisions of the 
frdnd have the appearance of rough ropes; upper and younger divisions 
clothed with longer and more slender branchlets, which bear alternate 
7 spreading plumules: similar plumules spring from ‘all parts of the shaggy 
: branches, growing among the regular ramuli. Plumules long and 
narrow, simply pinnate, straight ; pinnee erecto-patent, tapering to an acute 
point, and much narrowed at base. Articulations about twice as long as 
broad, somewhat constricted at the dissepiments. Tetraspores two or three 
together, elliptical, minute, sessile on the inner faces of short ramuli, which 
issue from the sides of the pinne. Fuavelle binate, borne on the pinne 
(frequently shortened) of less regular plumules. Colour a very dark, dull, 
brownish red. Swéstance rigid, not very closely adhering to paper, soon 
decaying in fresh water after the plant has been once dried, and then ex- 
haling the odour of violets. 
RRR RPI IIL PIII III IIL LPO 
