88 POLYSIPHONIA. 



These branches are usually simple, in luxuriant specimens furnished with 

 a second series, somewhat naked at base, in the upper part clothed with 

 slender, finely divided, irregular ramuli, which are either short, and giving 

 the branches a squarrose appearance, or elongated and divided, then giving 

 them the feathery character of P. violacea. Articulations of the stem in- 

 distinct, of the branches somewhat nodose, many-striate, and about as long 

 as broad, of the ramuli 2 or 3 tubed, rather longer than broad. Apices 

 splitting into numerous byssoid fibres. Colour a pale straw or somewhat 

 rosy when recent, becoming purplish in drying. Substance tender and 

 gelatinous, very fragile and soon decomposing. Capsules generally stalked ; 

 granules in distorted ramuli. 



SUB-GENUS 2. POLYSIPHONIA. Primary tubes six or more. 



* Frond partially inarticulate ; the articulations of the stem and branchet 

 obsolete, the surface-cells being small and irregularly shaped. (Siphons 

 seven). 



15. P. Brodicei, Dillw. ; stems inarticulate, robust, cartila- 

 ginous, alternately branched ; branches virgate, clothed with 

 spreading, pencilled, multifid, delicate, flaccid rarauli; arti- 

 culations of the ramuli 3 or 4 tubed, rather longer than 

 broad ; siphons of the stem about seven ; dissepiments trans- 

 parent. Harv. Phyc. Brit. t. cxcv. ; Hook. Br. Fl. ii. p. 

 328 ; Wyatt, Alg. Danm. No. 83. Conf. Brodiai, E. Bot. t. 

 2589. ft. subsimplex. Hutchinsia penicellata, Ag. Sp. 

 Alg. ii. p. 65. 



On rocks and the larger Algae, between tide-marks. Annual. Summer. 

 Common on most of our shores ; first noticed by the late Mr. Brodie, of Brodie, 

 near Forres. Frond 6 14 inches long, generally with an undivided, inar- 

 ticulate, robust stem, furnished with numerous alternate branches, which 

 are set at short distances with short, multifid, pencil-like ramuli, from half 

 an inch to an inch long ; the ramuli jointed, and repeatedly divided in an 

 alternate manner. Colour a dark brownish purple. Substance gelatinous, 

 instantly decomposing and giving out a disagreeable smell if immersed in 

 fresh water. ., which we have from Capt. Carraichael, who gathered his 

 specimens at Stafia, differs from the usual state of the plant in being less 

 branched, more rigid, of a darker colour and with more dense ramuli. 



** Frond articulated throughout; primary tubes six or seven. 



16. P. variegata, Ag. ; filaments brownish purple, seta- 

 ceous and rigid below, gradually attenuated upwards to a ca- 

 pillary fineness, dichotomous, the lower axils very patent; 

 branches somewhat zigzag, elongated, much divided, set 

 with lateral, capillary and very flaccid, multifid, purple ra- 

 muli ; articulations near the base shorter than their breadth, 

 in the principal branches twice as long as broad, in the ra- 

 muli short, marked with three broad, parallel, oblong tubes ; 



