Figs 8–14.

MATERIAL. 1. Russia, extreme Southeast of Saratov Oblast, 2–3 km East of Ozinki Town, in the steppe near the pool, 5.VII.2004, signals of one male recorded at 26–27 °C (Figs 8–11, 13).

2. Russia, Astrakhan Oblast, Western Shore of the Baskunchak Lake, near Bol’shoy Bogdo Mtn., 4.VII.2005, signals of two males recorded at 29–30 °C (Figs 12, 14).

SIGNALS. Calling signal is a very long phrase lasting from 40–50 s up to 3–4 min and consisting of two different parts. The first part consists of syllables repeating with a period of about 400–800 ms; syllable pattern is somewhat similar to this in the signal of P. laevus (cf. Fig. 9, the 1 st half of the oscillogram and Figs 1–2), but on high-speed oscillograms distinct interspecific differences are visible (Figs 10– 12 and 3–6). Similarly to P. laevus, amplitude relation of two parts of a syllable can differ in different signals (Figs 10–11 and 12). The second part of a phrase consists of partially merged short syllables with indistinct temporal pattern and repeating with a period of 40–70 ms.

PENIS SHAPE. The length ratio of the penis processes and their position are the same as in P. laevus, but the shape of penis stem is different (Fig. 14).