Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 71. (Budapest 1979)
Domokos, T.: On the morphological changes during ontogenesis of some Hungarian molluscs
of whorls is dependent of the growth rate of the second phase (Fig. 9). A comparison of the logarithmic spirals assumed on the two sides of the disk-shaped shell yields information not only on the radial growth of the shell but on its slight coning as well. (The radial growth of the spiral is different on the two sides of the shell, Fig. 4). The rotundity index of the cross-section of the whorls (Fig. 6) gradually increases with the growth of the shell in the case of Planorbarius corneus. In the course of growth, the oral aperture becomes angular in Anisus septemgyratus (Fig. 7) and round in Chondrula tridens (Fig. 15). In Unio species, the character role of the oral aperture is taken over by the edge of the shell. Its formal change can be characterized by the elongation (Fig. 17). During ontogenesis, the elongation increases according to a saturation curve. In Chondrula tridens (Figs. 11-12) the curve is nearly linear in the course of ontogenesis. Using mathematical formalism in malacology is somewhat out of date. Since, among others, also MOSLEY (1838), THOMPSON (1942), H. WAGNER (1929) and recently HUBENDICK (1951), FRANK & MEYLING (1966) have dealt with conchometry. Few are however, the works which, having some significance beyond mathematicizing may establish a relationship of the mathematical, physicochemical and biological parameters. Without establishing this relationship, a conscious study of the ecosystems cannot be envisaged. References DOMOKOS, T. (1976): Anisus septemgyratus (Rossmässler) és az Anisus leucostoma (Millet) fajok statisztikus vizsgálata I. Die statistische Untersuchung der Anisus septemgyratus (Rossmässler) und der Anisus leucostoma (Millet) Arten I. — Soosiana, 4: 57-60. DOMOKOS, T. (1977): Anisus septemgyratus (Rossmässler) és az Anisus leucostoma (Miilet) fajok statisztikus vizsgálata II/ 1. Die statistische Untersuchung der Anisus septemgyratus (Rossmässler) und der Anisus leucostoma (Millet) Arten II/ 1 — Soosiana, 5: 35-46. DOMOKOS, T. (1978): Az Anisus septemgyratus (Rossmässler) faj növekedési vonalairól. Über die Zuwachsstreifen von Anisus septemgyratus (Rossmässler). — Soosiana, 6: 45-50. DOMOKOS, T. (1979): A bélmegyeri (Békés-m.) rézkori Unio-félék statisztikus összehasonlítása recens anyaggal. Statistical comparison of Unio species of the Copper Age from the district Bélmegyer (Com. Békés) with recent material. — Békés megyei Múzeumok Közleményei, 6: in print. FRANK, G. H. & MEYLING, A. H. (1966): A contribution to the conchometry of Biomphalaria pfeifferi (Basomatophora: Planorbidae). •— Malacologia, 3 (3): 379-398. GEYER, D. (1929): Schlammschnecke Limnaea und ihre Anpassungsformen im Bodensee. — Natur. Mus. 59(7): 336-354. HUBENDICK, B. (1951): Anisus spirorbis and A. leucostomus (Moll. Pulm.), a critical comparison. — Ark. f. Zool., 2 (9): 551-557. MOSLEY, H. (1838): On the geometrical forms of turbinated and discoid shell. — Phil. Trans. R. Soc, 1: 351-370. Fig. 16. Characteristics of Bivaîvia: — = N, rjr b = R. — Fig. 17. Relationship between h (length) m and N (elongation). 1 = Unio pictorum, 2 = U. tumidus, 3 = U. crassus (Békéscsaba, Körös-ditch)
