Sek. GONGYLOSrERMEiE. ( 191 ) Fam. CERAMIACE/E. 



Plate CXXIX. 

 CALLITHAMNION GRANULATUM.— J". G. Acj. 



Gen. Char. — Fronds filiform and articulated, sometimes at length in tbe older parts 

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

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

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

 tripartite or cruciate. Name from KoXhs, " beautiful," and edfj.i/os, "a shrub." 



Callithamnion granulatum. — Fronds mvich tufted, stout and carti- 

 laginous, opaque, with veins below, pellucid above, much branched and 

 gradually tapering to a somewhat acute point ; primary branches often 

 again divided, all the branches thickly set with short capillaceo-multifid 

 ramuli; articulations short, contracted in the middle, and at the dis- 

 sejDiments. 



Callithamnion granulatum. — /. G. Agardh, Sp. Gen. Ahj. vol. ii. p, 61. 



Callithamnion spowp'iosMm. — Harv. in Eooh. Br. Fl. vol. ii. p. 346; Harv. in 

 Maclc. Fl. Hib. part 3, p. 217 ; Wyatt, Alg. Damn. No. 93 ; Crouan, 

 in Dcsm. PL; Harv. P. B. plate 125 ; Harv. Man. p. 182 ; Harv. Syn. 

 p. 155 ; Atlas, plate 57, fig. 265. 



Hab. — On rocks, stones, old shells, and parasitical on other Algse, near low-water 

 mark. Annual. Summer. Not very uncommon from Cornwall to Orkney. 



Geogr. Dist. — British Islands ; Atlantic shores of France. 



Description. — Fronds densely tufted, two to four inches high, rather 

 robust at the base, gradually tapering upwards, much and sometimes 

 repeatedly branched ; the branches long, mostly quadrifarious, and 

 everywhere set with short densely and repeatedly dichotomous ramvdi, 

 gradually tapering upwards, the terminal joints cylindrical, with a some- 

 what acute apex ; all the divisions erecto-patent, the axils rather acute. 

 Articulations of the main divisions two or three times longer than 

 broad, more or less opaque, with veins below, which arise fi-om the 

 bases of aU the branches and proceed downwards; upper articidations 

 pellucid and gradually but veiy slightly decreasing in length, so that 

 the apical joints are about the same projwrtionate length as the lower, 

 slightly contracted in the middle and at the dissepiments, every joint 

 furnishing its ramulus at its upper angle. Substance, in the mass soft 

 and spongy ; but the individual branches are rather firm and cartila- 

 ginous, closely adhering to paper. Colour, a dax-k brownish pui-ple, 



