P l a t e LXXVII.
CALLITHAMNION TRIPINNATUM, Ag.
G en . C h a e . VronA rosy or brownish red, fllamentous ; stem either opake
and cellular, or translucent and jointed ; branches Jointed, one tubed,
mostly pinnate (rarely diohotomous or irregular) ; dissepiments hyahne.
Fruit of two kinds, on distinct plants ; 1, external tetraspores,
scattered along the ultimate branchlets or borne on Httle pedicels ; 2,
roundish or lobed, beny-hke receptacles ( favellò) seated on the main
branches and containing numerous angular spores. C a l l i t h a m n i o n
[Ijynhg),— h om sáXKts, beautiful, and eo-pvlov, a little shrub.
C a l l i t h a m n i o n tripinnatum; frond distichously branched, oapiUary,
decomposito-pinnate; plumules elongate, obovate, tripinnate. above;
upper pinnæ elongate, and pinnulate, lower short or abortive, each
pinna having at its axil a minute pinnule ; pinnules long, setaceous ;
joints of the stem 3 -4 times, of the pinnæ about twice as long as
broad ; tetraspores oval, lateral on the axillary, and occasionally on
the other pinnules.
Ca l l it h a m n io n tripinnatum, Ag. Sp. Alg. vol. ii. p. 168. J. A g ì Alg. Medit.
p. 73. Fndl. 3rd Suppl. p. 34. no. 23 Jbut not o f Harv. in Hook. Br. FI.
vol. ü.^i. 346. nor o f Wyatt, Alg. Banm.p. 186.). “
M e e t e n s ia tripinnata, Gratel. MS. sec. Ag.
H a b . On marine rocks, at extreme low water mark. Annual April,
May. Very rare. Roundstone Bay, Mr. Me Calla.
G e o g e . D is t b . Coast of France, Grateloup. Mediterranean Sea, J. Agardli!
West of Ireland, very rare.
D e s c e . Fronds tufted, from one to two inches high, capillary, membranaceous,
not gelatinous, perfectly distichous, having a circumscribed, somewhat fanshaped
outhne, about triply pinnate ; the primary pinnæ, or plumules (one
of which is represented at figure 2 ) having a narrow obovate outline, thefr
lower pinnæ being very short, and simple, those approaching the middle of
the rachis, graduaUy longer, those just beyond the middle longest, and
those from thence to the apex gi-adually shorter. The upper and middle
pinnæ have their upper half fm-nished with slender, setaceous, elongate,
patent, alternate pinnules ; thefr lower half naked, except the basal joint,
which bears, almost invariably, at its upper side, or in the axü of the pinna,
a solitary, and very frequently fertile, pinnule. Except for this basal pinnule,
the lower pinnæ are quite naked, and generaUy very short or abortive.
All the divisions are alternate. The joints of the stem and branches are
peUucid, from three to four times longer than broad, cylindrical or somewhat
swollen at the nodes ; those of the pinnules are about twice as long as
broad. Tetraspores oval, with wide borders, secund along the upper edge
of the ultimate pinnules, very commonly on the axUlary one. Favellæ
unknown. Colour a full dark red. Substance delicate, and closely adhering
to paper in drying.
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