178 CALL1THAMNION. 



or spherical, on the inner faces of the ratnuli, 2 or 3 together or solitary. 

 Favellce two or more together on the branches. Colour in young specimens 

 a fine purple-red, in old brownish, becoming brighter in fresh water. 



15. C. byssoideum, Arnott ; stems extremely slender, flac- 

 cid and byssoid, much divided ; branches linear-lanceolate, 

 set with long, slender, flexuous, sub-simply pinnate plumules ; 

 joints of the branches eight times, of the ramuli four times 

 longer than broad ; tetraspores solitary, sessile on the pinnae. 

 Harv. in Hook. Br. FL ii. p. 342; Wyatt, Alg. Damn. No. 

 185 ; Harv. Phyc. Brit. t. cclxii. 



Near low-water mart, on other Alga?. Whitsand Bay, Dr. Jacob. Not 

 very uncommon. Stems extremely tender, flaccid and gelatinous, much 

 divided from the base, either with several principal branches thicker than 

 the rest, which bear a great number of lesser branches, or wholly composed 

 of slender, byssoid branches, inextricably entangled together, the main 

 stems in the coarser specimens full of veins ; branches having a linear-lan- 

 ceolate outline, tapering to a point, clothed with long, slender, sub-simply 

 pinnate ramuli, either quadrifarious or distichous, all the divisions alter- 

 nate. Joints of the stem many times longer than broad, of the ramuli 

 about four times longer than broad. Tetraspores elliptical, sub-solitary 

 near the base of the ramuli. Favellce sessile on the stems, frequently three- 

 lobed. This species has the habit and substance of Cal. corymbosum, with 

 which, at one time, I was disposed to unite it. In ramification, however, 

 it more nearly agrees with C. roseum, but is much more slender and 

 delicate. 



16. C. polyspermum, Ag. ; tufts globose ; filaments slen- 

 der, delicate, loosely branched, somewhat naked below, disti- 

 chously plurnulate above ; plumules linear-oblong (in out- 

 line); pinnae short, simple, patent, acute, spine-like ; articu- 

 lations of the branches 4 or 5 times, of the ramuli twice as 

 long as broad ; tetraspores lining the inner faces of the pin- 

 na?. Harv. in Hook. Br. FL ii. p. 342 ; Wyatt, Alg. Danm. 

 No. 140 ; Harv. Phyc. Brit. t. ccxxxi. 



On rocks and the larger Fuci, not uncommon. Annual. Spring and 

 summer. Tufts globose, 1 3 inches in diameter, dense; stems sub- 

 simple below, much branched above in a fan-like manner ; the branches 

 several times divided and set with lesser branches, all the larger ones hav- 

 ing spine-like, alternate, subulate, short ramuli, the larger pinnated with a 

 second series, the uppermost ones occasionally still more compound ; all 

 the ramuli spreading, sometimes reflexed. Joints of the stem and branches 

 torulose, with a narrow tube. Capsules profuse, spherical. Favellce large, 

 roundish or ovate, binate. Colour a dull rose-red or purplish. In drying 

 it adheres less perfectly than some others to paper. 



17. C. purpurascens, Sm. ; "purplish-red, repeatedly 

 branched, very slender and tufted, joints slightly turned, 

 thrice as long as broad, with pellucid partitions, those of the 



