FIGURE 4 in Deciphering "cryptic" nature of European rock-dwelling Pyramidula snails (Gastropoda: Stylommatophora)

FIGURE 4 Position of measured shells along the first two axes of the Canonical Variance Analysis based on the fifteen measured shell parameters and their ratios (supplementary table S2). Numbers of measured shells / populations for each species: P. jaenensis: 29 / 7, P. saxatilis: 50 / 11, P. rupestris: 28 / 9, P. pusilla: 55 / 12. Convex polygons were added to the diagram to highlight the distinction between the four species. Type specimens of the respective species were also used in the analysis (see fig. 7 for details), and are shown in grey color. Variation in selected basic shell parameters among the four species (PP, P. pusilla; PS, P. saxatilis; PR, P. rupestris; PJ, P. jaenensis) is visualized using notched box-and-whisker plots on the right.