Folia Historico-Naturalia Musei Matraensis - A Mátra Múzeum Természetrajzi Közleményei 6. (1980)

Domokos, T.: Adatok az Anisus vortex L. faj morfometriájához

Fig. 2. Relationship between log lOR and WN. — Fig. 3. Relationship between m and WN. similar to the higher values of Baja (DOMOKOS, 1977). Figure 3 shows unambiguously that the term (m), supposed to be constant, of the exponent characterizing the pace of growth changes gradually and decreases to about half. That means, naturally, that the radial growth of the whorls of A. vortex gradually slows down. The results connected with the characterization of the shell-spiral are contained in histograms R

—WN, in graphs (Figs. 4—11), as well as in a table. The modes R of the two biotopes show a good agreement. The modes of the individuals of the Szántód biotope area perhaps somewhat greater (Fig. 10). The WN dependence of the parameter R of the Szántód material can be described with a good approach by the following power function :B= 0.15 K

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78 (Fig. 11). The approach is very good over WN—3, and the deviation is only a few percent. On the basis os the figures (Figs. 4—9) and the table it can be found that the groups of 25 specimens already gie a relatively well reproducible result, and it is only with higher whorls that a more significant deviation is to be experienced. 177