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, longitudinal 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 densissime 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 subdistichis 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. Articuli 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, differently 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.
