182 FLOKA ANTARCTICA. {Auckland and 



belongs. The internal structure of the stem is similar to that of P.fruticulosa, but there are fewer radiating fibres, 

 and is quite unlike that of Mod. subfusca. There are two varieties, one more robust, flexuous and densely branched 

 than the other ; but they do not appear specifically distinct. Both bear capsidar fruit, of a peculiarly clustered 

 character, different from that of any other Polysiphonia, and we regard it as the principal distinction on which the 

 species rests. The capsules are farther remarkable for their minuteness in proportion to the plant producing them. 

 Their number, however, compensates for size, thirty or forty occupying a space not greater than that of a capsule 

 of the dimensions usual in this genus. 



Plate LXX. Fig. 1, portion of a stem of the natural size; 2, branch and ceramidia ; 3, ceramidium; 4, lon- 

 gitudinal section of the same ; 5, spores; 6, branch and stichidia ; 7, stichidium ; 8, sphaerospores : — magnified. 



%. Polysiphonia Lyallil, Hook. fil. et Harv.; caule cartilagineo setaceo inarticulato alterne vel vage 

 ramoso, ramis elongatis simplicibus inarticulatis ramulis brevibus articulatis quadrifariis multifidis densis- 

 sime vestitis, ramulorum articulis diametro aequalibus 3-5 veuosis. (Tab. LXXFV. Fig. I.) 



Hab. Lord Auckland's group. (Dr. Li/all.) 



Caulis erectus, 4-5 unc. longus, validus, simplex v. basi divisus ; ramis paucis, elongatis, alternis v. secundis, 

 simplicibus ; caulis et rami inarticulati, densissime e basi ad apicern ramulis brevibus 1 lin. longis obsiti. Ramuli 

 articidati, quadrifarii, patentissimi irregulariter multifidi, nunc fere dichotomi, alterne v. secunde partiti ; ultimi 

 subulati, acuta, patentes v. recurvi. Articuli 3-5-striati, diametro subaequales v. vix longiores. Color intense 

 fusco-ruber. Fructus . . . . ? Siphones in ramis majoribus quatuor, magni, tubulum centralem angustum cruciatim 

 cingentes, cellulis irregidaribus peripheriam versus sensim miuoribus cireumdati. 



We have much pleasure in naming this very distinctly marked and beautiful species after its discoverer, Dr. Lyall. 



Plate LXXIV. Fig.l. — 1, plant of the natural size ; 2, branch; 3, portion of stem ; 4, ditto of branch : — magnified. 



3. Polysiphonia dumosa, Hook. fil. et Harv.; caule erecto rigido flabellatim ramoso inarticulato, ramis 

 patentibus alternis v. subdichotomis elongatis, ramulis distantibus aequalibus brevibus patentissimis sub- 

 distichis laxe pimiatis subulatis, articulis ramulorum brevissiniis. (Tab. LXXV. Fig. I.) 



Hab. Campbell's Island ; parasitic on the stems of large Alga. 



Caules caespitosi, 1-3 unc. longi, erecti, cylindracei, basi simplices, sursum flabellatim ramosi v. irregulariter 

 dichotome v. alterne clivisi. Rami simplices v. divisi, per totam longitudinem ramulis 1-2 lin. longis, horizontali- 

 patentibus subdistichis laxe pinnatis obsiti. Pinnulis patentes, subulatae, acutae, strictae, curvatae v. tortae. Arti- 

 culi in ramulis tantum manifesti, brevissimi, 3-5-striati. Siphones ramidini quatuor, niagni, tubulum centralem 

 angustum cruciatim cingentes, cellulis irregularibus peripheriam versus sensim miuoribus cireumdati. Color badius, 

 apices versus fusco-ruber. Substantia rigida. — Chartae vix adhaeret. 



Allied to P. Lyallii, but much smaller in all its parts ; of a duller colour and more rigid substance, dift'erently 

 branched and with less dense ramuli, which are nearly, though not strictly, distichous. In aspect, it somewhat 

 resembles P. ceratoclada, though quite unlike that species in internal structure. 



Plate LXXV. Fig. I. — 1, portion of a branch ; 2, stem and branch ; 3, section of stem : — magnified. 



4. Polysiphonia punicea, Mont. ; punicea, caule vage ramoso articulato setaceo flexuoso, ramis alternis 

 v. secundis subremotis, ramulis alternis remotiuscuhs flabellato-dicliotomis abbreviatis patentissimis ultimis 

 subulatis recurvis, articulis ramorum diainetro 3-4-plo longioribus 3-5-venosis ramulorum subquadratis 

 biveniis pellucidis apicibus acutis, " capsulis subsessiHbus ovato-acumiuatis " (Mont.), sticludiis lanceolatis 

 sphaerosporas pluriseriatas includentibus, ceramidiis sessilibus solitariis urceolatis, ore contracto porrecto. P. 

 punicea, Mont. Prodr. Fhyc. Antarct. p. 6. Yoy. au Pole Sud, Pot. Cryjrt. p. 128. t. 5. f. 3. 



