CALLITHAMNION. 177 



Dillw. t. 106. C. latiosiim^ Harv. I. c. ; Wyatt, Alg. Datim. 

 No. 139. 



On rocks and Algas between tide-marks. Annual. Spring and sum- 

 mer. Cawsie, Messrs. Hooker and Borrer. Not uncommon, from Orkney 

 to Cornwall. — Stem 1 — 3 inches high, setaceous, inarticulate or spuriously 

 jointed (the joints short and filled with veiny fibres), closely furnished 

 throughout with long, simple branches, similar to itself, which again bear 

 a second or third set, either quadrifarious or sub-distichous, flexuous ; the 

 lesser ones jointed, and at the joints bearing very patent, pinnated ramuli 

 or plumules, which are sometimes naked at the base, and either simple or 

 bipinnated above, all the pinnules very patent or divaricating. Joints 

 twice or thrice as long as broad. Tetraspores along the inner face of the 

 ramuli near the base, either solitary or 2 or 3 together. Favella large, on 

 the branches, irregular. Colour a brownish or rosy-red, in some states pre- 

 served in drying, at other times very fugacious. The specimens of this 

 plant from North Devon and from the South of Ireland, are much more 

 robust and deeper coloured, and of a less delicate substance than those 

 from Torbay and the east of Ireland, and, at first sight, strikingly resemble 

 C. Brodiai, while the latter come nearer C. roseum. A re-examination of 

 the original Conferva Hookeri, and comparison with various varieties of 

 Cal. lanosum, Br. Fl. induce me to unite the latter to the former. It is 

 certainly a very variable plant, but the varieties run insensibly into each 

 other. 



Section 3. Rosea. Main stems slender, evidently articu- 

 lated, the articulations pellucid, or traversed by a few 

 longitudinal filaments. Branches decomj)Ound-pinnate. 

 Ramuli alternate. (Sp. 14 — 23). 



14. C. roseum, Sm. ; stems much and loosely branched; 

 secondary branches long, flexuous, sub-distichously plumu- 

 late ; plumules lax, with a roundish outline, crowded towards 

 the tops of the branches ; pinnules long, patent, sub-simple, 

 curved, simply pinnate ; main articulations 4 or 5 times, 

 those of the pinnae 2 or 3 times longer than broad ; tetra- 

 spores elliptical, scattered, near the base of the piimae. Harv. 

 Hook. Br. Fl. ii. p. 341 ; Wyatt, Alg. Damn. No. 44 ; 

 Harv. Pliyc. Brit. t. ccxxx. Conf. rosea, E. Bot. t. dGQ. 



Near low-water mark, on mud-covered rocks and Algge. Annual. Sum- 

 mer. Yarmouth, Messrs. Turner and Borrer. Not uncommon, generally 

 distributed. — Stems 3 or 4 inches long, setaceous, in young plants jointed, 

 in older opake and full of veins, set throughout with long, more or less qua- 

 drifarious, patent branches, which are several times irregularly pinnated, 

 till the plant acquires an excessively branched, entangled character; 

 branches furnished more or less abundantly with long, simply or sub- 

 simply pinnated plumules, which are usually crowded in the upper part of 

 the branches, giving the tips (especially of young plants) a dense appear- 

 ance ; the ultimate ramuli elongate, slender, the lower ones usually simple, 

 the upper occasionally pinnulate in the upper part. Tetraspores elliptical 



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