78 BYNOP8I8 OF BRITISH sr..\ WKEDS. 



u-dhiana, Orev. V. badia, Qrev. P. denudata. 



Hutchiimia afaro-rubesceng, Lyngb. H. Agardhiana, 



.•1//. JI. badia, .1//. H. denudata, il^. Conferva nigra, Hnd*. 



C. atro-rub . 0. badia, Dho, C. deDudata, Z)fa 



7/^/y. On rucks and Btonefl in I lie >ea, near low-water mark. An 

 nnal. Summer and autumn. Nol uncommon. 



So long a string of synonyms Beems to speak of a plant 

 of very variable aspect. Yet the species here figured is 

 tolerably constant to its characters, and much less variable 

 than some others of the genus, about which botanists have 

 had fewer differences. This plant has appeared under four 

 names in the works of most authors ; the first, P. badia, 

 refers to the frond in a half-grown state ; P.atro-rubescens, 

 to the ordinary form of the full-grown plant; P. Agardh- 

 iana, to a luxuriant state of the frond, coupled with an 

 imperfect state of capsular fruit ; and P. denudata, to a 

 battered and denuded state of the frond. 



126. furcellata (The forked Polgnphonia); filaments elongated, 

 tufted, flexuous, repeatedly and closely dichotomous ; axils 

 broad, rounded ; rainuli erect, their points somewhat hooked 

 in ; joints of the stem three to five times longer than broad, 

 Hare, in Hook. Br. Fl. v. 2. p. 332. (Atlas, PL XXVIII. 

 Fig. 126.) 



Hutchinsia furcellata, Ag. Lamourouxia turgidula, Bonnem. 

 Hah. South shore of England. Annual. Summer. Very rare. 



This species, figured for the first time in the ' Phycologia 

 Britannica,' as rare as it is beautiful, till it was recently 

 brought by Mr. Webb from the Canary Islands, was sup- 

 posed to be confined to the shores of the British Channel. 

 There is no other British species so nearly allied to P. fur- 

 cellata as to be confounded with it, although when examined 

 microscopically we perceive a considerable affinity on the 

 one hand to P. nigrescens, and on the other to P.fastigi- 

 ata. Between these two species indeed, P. furcellata ap- 

 pears to me to be almost intermediate. The relative length 

 and the structure of the joints are very much those of P. 

 nigrescent, from which the dichotomous, not pinnate, rami- 

 fication, the want of leading stem, bright colour, etc., abun- 

 dantly distinguish it ; while, on the other hand, the rami- 

 fication nearly approaches that of P.fasfigiaia ; but then, 

 the nature of the joints, the colour, and the flaccid sub- 

 stance are very different. 



127. fastigiata ( The level-topped Polysiphonia) ; filaments 



