Art. XXXVII.—Notes on Fresh-water Algæ.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 15, 1882, Page 302

Art. XXXVII.—Notes on Fresh-water Algæ. By W. I. Spencer, M.R.C.S. [Read before the Hawke's Bay Philosophical Institute, 9th October, 1882.] Plates XXVI. and XXVII. In continuation of the Catalogue of the Fresh-water Algæ occurring in the vicinity of Napier, which I laid before you last year,*“Trans. N.Z. Inst.,” vol. xiv., art. xliii. I beg this evening to call your attention to the following additions which have come to my notice since then. Draparnaldia sp.?. Fig 1. Filament branched, ¼00 in diameter, tapering towards apex, cells as long as, or twice as long as broad. Branchlets (ramuli) bipinnate ½266 in diameter, cells slightly longer than broad, terminal ones pointed, tufted, near apex filament gives out a large number of elongated jointed processes, which are mostly simple, but sometimes branched. I am indebted for this plant to Mr. Hamilton, who discovered it in the Horokiwi stream. Possibly a variety of D. glomerata. Cladophora pacifica, Kuch. Montague (Voy. au Pôle Sud) mentions this as having been found in Lord Auckland's Group. Cladophora longiarticulata, Kuch. Found by Nordstedt in the Sandwich Islands. Staurocarpus. Spirogyra, sp. n. Fig 2. Cells square, very rarely twice or four times longer than broad, this probably only when on the point of dividing, ends slightly convex, never retracted. Endochrome arranged in three distinct straight bands at rightangles to wall of cell, and with no visible connection. Each band consisting of three or four minute round cellules, containing chlorophyl!. Sporange formed in parent cells, globular. Cells.—Diameter, 1/700; length, 1/700, rarely ⅓50 or 1/175. Zygospore 1/1400 in diameter. This little plant is easily recognized by the rigidity of the filament, the masonic regularity with which the cells are arranged—the convex ends of which just touch—and the singular arrangement of the endochrome. Common. Zygnema, sp. n. Fig. 3. Ends of cells retracted. Contents consist of twin stellate masses of endochrome. Zygospore lodged in the filament, oval, filling but not bulging the cell. Spore bearing cell appears to be somewhat smaller than the others.

Filament.—Diameter 1/500″. Length of cell.—⅓50″ to ⅓80″. Zygospore.—Length, ¼12″ breadth, 1/700″. Diameter of sporiferous cell, 1/700″. From Ruataniwha. Zygnema, sp. n. Fig. 4. Cells retracted at the ends. Eleven or twelve lines longer than broad. Zygospore globular, lodged in the connecting tube, the length of which varies considerably. Filament.—Diameter, 1/1400″. Cells.—Length, 1/107″ to 1/126″. Diameter of zygospore, 1/1000″. Length of connecting tube from ⅓50″ to ¼66″. Also from Ruataniwha— Bulbochœte setigera. œdogonium princeps. Vaucheria sessilis. Rivularia iridis. Oscillatoria and Vibrio. A series of the last-mentioned plants I found in samples of water from the hot springs at Taupo, growing in water the temperature of which varied from 105° F. to 136°. They all exhibited the motions peculiar to this class of Algæ. Fig. 5. (a) Oscillatoria sp., contains a row of cells; diameter of filament, 1/500″. (b) Vibrio, alternate dark and light cells; diam., 1/14000″; temp., 105°. (c) Oscillatoria, diam., 1/7000″; temp., 116°. (d and e) probably the same although varying much in diameter, which is ½300″ and ⅓500″; temp., 116° and 130°; (f) temp. 136°, diam. 1/14000″. This plant is so unlike an Oscillatarian that had it not been for the movements, which consisted of both side-way motion and also progression and retrogression, I should not have recognized it. (g) Oscillatoria, diam., 1/7000°; striæ evident, close; temp., 136°. I have found about 12 Desmids not hitherto discovered in this country, one of which is probably new. My time, however, has not permitted me to include them in these notes. Mr. Maskell, of Christchurch, has therefore undertaken their description, and they will be found in his paper. * Art. XXXI., supra. Fragillaria pectinalis. Gomphonema acuminatum. Gonium pectinale.

Description of Plates XXVI. and XXVII. Fig. 1. Draparnaldia. 2. Spirogyra. (a) filaments conjugating. (b) zygospore. (c) the same commencing to grow. 3. Zygnema. 4. Zygnema. 5. Oscillatoriæ from Taupo.