Ser. RHODOSPERMEZ. Fam. Ceramiee. 
Puate LXXVII. 
CALLITHAMNION TRIPINNATUM, “4%. 
Gen. Cuar. Hrond 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 hya- 
line. rwit of two kinds, on distinct plants; 1, external tetraspores, 
scattered along the ultimate branchlets or borne on little pedicels; 2, 
roundish or lobed, berry-like receptacles (favel/e) seated on the main 
branches and containing numerous angular syores. CALLITHAMNION 
(Lynbg.),—from xarus, beautiful, and dapviov, a Little shrub. 
CaLLITHAMNION tripinnatum; frond distichously branched, capillary, 
decomposito-pinnate ; plumules elongate, obovate, tripinnate above ; 
upper pinne elongate, and pinnulate, lower short or abortive, each 
pinna having at its axila minute pimnule; pinnules long, setaceous ; 
joints of the stem 3-4 times, of the pinne about twice as long as 
broad ; tetraspores oval, lateral on the axillary, and occasionally on 
the other pinnules. 
CALLITHAMNION tripinnatum, 49. Sp. Aig. vol. ii. p. 168. J. Ag! Alg. Medit. 
p- 72. Endl. 3rd Suppl. p. 34. no. 23 (but not of Harv. in Hook. Br. Fl. 
vol. u. p. 346. nor of Wyatt, Alg. Danm. p. 186.). 
MERTENSIA tripinnata, Gratel. MS. sec. Ag. 
Has. On marine rocks, at extreme low water mark. Annual. April, 
May. Very rare. Roundstone Bay, Mr. Mc Calla. 
Groer. Distr. Coast of France, Grateloup. Mediterranean Sea, J, Agardh! 
West of Ireland, very rare. 
Descr. Fronds tufted, from one to two inches high, capillary, membranaceous, 
not gelatinous, perfectly distichous, having a circumscribed, somewhat fan- 
shaped outline, about triply pmnate; the primary pinne, or plumules (one 
of which is represented at figure 2) having a narrow obovate outline, their 
lower pinne being very short, and simple, those approaching the middle of 
the rachis, gradually longer, those just beyond the middle longest, and 
those from thence to the apex gradually shorter. The upper and middle 
pinne have their upper half furnished with slender, setaceous, elongate, 
patent, alternate pinnules; their lower half naked, except the basal joint, 
which bears, almost invariably, at its upper side, or in the axil of the pinna, 
a solitary, and very frequently fertile, pimnule. Except for this basal pin- 
nule, the lower pinne are quite naked, and generally very short or abortive. 
All the divisions are alternate. The joints of the stem and branches are 
pellucid, from three to four times longer than broad, cylindrical or some- 
what swollen at the nodes; those of the pinnules are about twice as long as 
broad. etraspores oval, with wide borders, secund along the upper edge 
of the ultimate pinnules, very commonly on the axillary one. Fuvelle 
unknown. Colour a full dark red. Substance delicate, and closely adhering 
to paper in drying. 
ee 
