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. violncea. Articulations of the stem in- 

 distinct, of the branches somewhat nodose, many-slriate, 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. Polystphonia. Primary tubes six or more. 



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

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

 seven). 



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

 ginous, alternately branched ; branches virgate, clothed with 

 spreading, pencilled, multifid, delicate, flaccid ramuli ; 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. Damn. No. 83. Co;?/. Brodiiei, E. Bot. t. 

 2589. — /3. suhsimplex. 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 J/r. 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. Coloiir 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 Statfa, 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 ; 



