Ser. GONGYLOSPERME^. ( 175 ) Fam. CERAMIACE^. 



CALLITHAT^INION POLYSPEEMUM.— ^i/. 



Gen. Char. — Fronds 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. Favellae, mostly 

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

 tripartite or cruciate. Name from KaXhs, "beautiful," and ddfivos, "a shrub." 



Callithamnion pohjsjyeronnm. — Fronds rather slender and delicate, 

 much tufted and irregularly branched, distichous, and repeatedly 

 pinnate iipwards ; pinnse long, slender, and scarcely tapering, pinnules 

 shoi-t, subulate, slightly recurved ; articulations of the main branches 

 four to five times longer than broad, shorter upwards. 



Callithamnion polyspermum. — Ag. Sp. Alrj. vol. ii. p. 169 ; Wyatt, Alg. Danm. 

 No, 140 ; Endl. 3rd Suppl. p. 34 ; Harv. in Hook. Br. Fl. vol. ii. 

 p. 342 ; Harv. m Mack. Fl. Ilib. part 3, p. 214 ; Harv. P. £. 

 plate 231 ; Harv. Man. p. 178 ; Harv. Syn. p. 150 ; Atlas, plate 58, 

 fig. 270 ; Harv. N. B. A. part 2, p. 234 ; J. G. Agardh, Sp. Gen. Alg. 

 vol. ii. p. 48. 



Callith AMNION GrevUlli. — Harv. in Hook. Br. Fl. vol. ii. p. 345 j Harv. Man. 

 1st ed. p. 110 ; Harv. in Mack. Fl. Hib. part 3, p. 215. 



Callithamnion roseum. — Grev. Fl. Edin. p. 311 (not of jB;-. FL). 



Callithamnion purpurascens. — Johnst. Berw. Fl. vol. i. p. 240. 



Phleboxhamnion polyspermum. — Klitz. Pliyc. Gen. p. 374. 



Hab. — On Fucus vesiculosus and serratus, as well as other Algae, between tide marks. 

 Annual. Summer. Common. 



Geogr. Dist. — Atlantic shores of Europe. 



Description. — Root, a minute disc. Stems very slender, much tufted, 

 one to two or three inches in length, very much branched ; lower 

 branches somewhat u'regular and scattered, long, slender, and flexuous, 

 more regulai-ly distichous upwards, and two to thi-ee times pinnate ; 

 pinnae long, slender, and flexuous, scarcely tapering ; pinniolse short, 

 recurved, subulate, of nearly equal length, giving the pinnae a narrow, 

 linear lanceolate outline. Articulations of the branches three to four 

 times longer than broad, gradually shorter uj)wards ; those at the base 

 of the stem having a few jointed fibres proceeding from the bases of 

 the lower branches, but not so numerous as to render the joints indis- 

 tinct or opaque ; those upwards entirely free from fibres, somewhat 

 contracted at the dissepiments and in the middle. Substance very 

 flaccid, and adhering closely to paper. Colour, a fine brownish lake. 



