SiiK. UONGYLiOSrKlLME.E. ( 1511 ) Fam. CEKAMIACE.E. 



Plate CXIX. 

 CALLITHAMNION AIIBUSCVLA.—Zijugh. 



Gi:n. Chak. — Fron'ls filiform and articulated, sometimes at length in the older parts 

 cellular and partially opaque, single-tubed ; divisions mostly pinnate, dissepiments 

 hyaline. Fructification of two kinds, on distinct plants : 1. Favellfe, mostly 

 lateral on the branches, and filled with minute spores ; 2. Tetraspores, external, 

 tripartite or cruciate. Name from KaXhs, "beautiful," and 6d/j.vos, "a shrub." 



Callithamnion arbuscula. — Stems rather stout, naked and opaque 

 at the base, much divided and very bushy upwards; ultimate ramuU 

 pinnate, with alternate, mostly simple, rather long, setaceous, recui-ved 

 pinnules, the upper edges of which are fringed with sessile, spherical 

 tetraspores ; articulations twice as long as broad. 



Callithamnion arhuscula ■ — Lyngh. Hyd. Dan. p. 123, t. 38 ; Harv. in Hoolc. 

 Br. Fl. vol. ii. p. 340; Harv. in Mach. Fl. Hih. part 3, p. 213; 

 Harv. P. ^. plate 274 ; Harv. Blan. p. 174; Harv. Syn. p. 145; 

 Atlas, plate 57, fig. 262; /. G. Agardh, S}). Gen. Ahj. vol. ii, p. 60. 



Phlebothamnion arbuscula. — Riitz. Sp. Alg. p. Q5Q. 



Dasya spongiosa. — Ag. Sp. Alg. vol. ii. p. 121. 



CoHFERYA arluscula.—R. Br. Dillw. t. 85 (excl. t. G.) ; E. Bot. t. 1916. 



Hab. — On mussel-shells near low-watermark, left bare by the tide. Perennial. Summer 

 and autumn. Common on the "west coasts of Scotland and Ireland. Rare on the eastern. 



(lEOGE. DiST. — Faroe Islands. 



Description. — Root, a rather largo flat conical disc. Fronds very 

 bush}', two to four inches or more in length, and from half a line to a 

 line in diameter, naked for half an inch or an inch or more, but 

 sometimes branched even from the base, most densely upwards, the 

 branches spreading on all sides, longest near the base, giving the frond a 

 conical outline, the ultimate branchlets more or less zigzag, producing at 

 the summit of each articulation alternate, slender, simple or forked 

 tapering pinnse, which are patent or more or less recurved. Towards 

 the sumiuit the ramuli are extremely dense, giving the plant a very 

 thick bushy appearance upwards. Substance somewhat cartilaginous in 

 the older part, soft and flaccid in the younger, and adhering closely to 

 paper, but when the plants become old they adhere veiy imperfectly. 

 Colour, a deep brownish pui'ple or reddish brown, darker when old. 

 Favellre lobed, minute, arising from the sides of the ramidi. Tetraspores 

 numerous, fringing the upper edge of their piimse. 



