Szekessy Vilmos (szerk.): A Magyar Természettudományi Múzeum évkönyve 53. (Budapest 1961)

Halász, M.: The microvegetation of the acrothermae of Harkány

Fam. : PLEUROCAPSACEAE Genus : Onkonema Geitler, 1933 Onkonema compaction Geitler, 1933 (Fig. 2) Geitler. Arch. f. Hydrobiol., Suppl., 12, 1933, p. 627 ; Suppl., 14, 1936, p. 410, fig. 39, 40. Specimens occurring in Harkány agree with description of type, with some differences in dimensions of single cells only. Cells nearly quadrangular or slightly pupiform, mostly shorter than long, 3,5—4 LI broad, constituting by branching irregularly arranged filaments. By longitudinal division and apical growth, branching, filamentous cell groups develop (attaining 8,4 LI in thickness) out of initial, uniserial filaments. Apical cell elongated, tapering. From unilateral cell filaments, 2 to 4 or more lateral branches develop by lateral distension of single intercalar cells. Of polyserial filaments, by three-dimensional division, crregularly arranged cell groups may develop, forming chroococcoidal stage ionsisting of small-sized (2—3) cells. In such cases, filamental structure disappears, and 2 — 3 LI large, more or less adpressed to each other and therefore polygonal, cells may be liberated as nannocytae. Cells violet-bluish. Occurrence: a) Spring outlet in Harkány: d) Java (Geitler&Ruttner 1936). Fam. : STIGONEMATACE AE Genus : Hapalosiphon Naegeli, 1849 Hapalosiphon laminosus (Kütz.) Hansg., 1885 (Fig. 27 a, b) Merizomyria laminosa Kütz., Phyc. gen., 1843, p. 232 ; Tab. phycol., 2, 1845—49, p. 13, T. 45, f. 1 ; Mastigocladus laminosus Cohn, Abh. Schles. Ges. Vaterl. Kultur, 1863, p. 39 ; Hapalosiphon laminosus (Kütz.) Hansgirg, Bot. Zentralblatt, 22, 1885, p. 48 ; Born, &Fla h., Revis, des Nostoc, Ann. Sei. Nat. Bot., 7, 1887, p. 55 ; Aulosira thermalis G. S. West, Journ. of Bot., 40, 1902, p. 244; Nostoc anisococcum Schwabe, Liimaea, 1837, p. 126, T. XIV. Specimens occurring in Harkány may be found as expanded layer or scattered filaments, that is, filamental fragments (these latter among filaments of filamentous algae of other Cyanophyton communities). Coatings form spongy, coriaceous structure, 1 — 3 mm thick. Layer compact, crustaceous, rather tough, sometimes lamellated. Color ranging from dingy olive green to bluish-green or whitish bluish-green. Filaments densely interwoven, unequally developed. Young filaments thin, articulation into joints indistinct, Lyngbya-like, unbranched. Developed filaments 4—6 p thick, curved, containing single row of cells, sometimes two rows. Tilden, too (Minnesota Algae, 1910, p. 240, Pl. XIV, f. 14, 15) records these primary filaments of two rows, to wit : "filaments interwoven, showing great variety of form . . . often constricted at joints, containing a single row of cells, rarely two rows . . ." On the other hand, Geitler (1931, p. 557) mentions but uniseriate filaments in his diagnosis of the genus : „Faden einreihig, bei typischer Ausbildung meist einseitig, schmalen Seitenzweigen besetzt". Again, Hansgirg (Prodr. Algenfl. Böhmen, 1892, p. 27), who designates by the name Mastigocladus (Cohn) only a section of the genus Hapalosiphon Naeg., writes as follows in the diagnosis of the species : „Völlig entwickelte Faden . . . aus einer, stellenweise auch zwei Zellreihen bestehend . . ." W. West notes this circumstance, too (The British Freshw. Algae, 1904, p. 321). I observed also on one or two occasions these two rows of cells on the primarv