Monacha (Paratheba) kuznetsovi, Hausdorf, 2000

Hausdorf, Bernhard, 2000, genus Monacha in the Western Caucasus Gastropoda: Hygromiidae), Journal of Natural History 34, pp. 1575-1594 : 1581-1583

Monacha (Paratheba) kuznetsovi , sp. n.

(®gures 2, 11, 17)

Helix frequens, Mousson 1863: 318 [partim, non Mousson, 1859].

Helix frequens, Rosen 1911: 101 [partim, non Mousson, 1859].

Shell (®gure 2). Depressed conical±globular; with 5 ½ ±5× convex whorls; teleoconch with wrinkled growth-ridges and Ô indistinct incised spiral striae; light corneous; body whorl rounded; aperture almost circular; upper insertion of the peristome slightly descending; peristome sharp, not expanded, with a whitish internal rib; umbilicus narrow, partly obscured by the reēcted columellar edge.

Measurements. SW slope of the Markotkh Gora (n 5 7): D: 12.1±13.7 mm, x Å 5 12.8 mm; H: 8.4 ±9.8 mm, x Å 5 9.1 mm; D/H: 1.37±1.49, x Å 5 1.41.

Genitalia (®gure 11). The short penial papilla is Ô conical. The long and slender basal section of the appendicula is delimited from the short, hardly expanded apical section by a distinct narrowing. The two glandulae mucosae are slightly rami®ed. The bursa of the bursa copulatrix is Ô rounded triangular. The right ommatophoral retractor crosses with the penial retractor. The measurements of some sections of the genitalia are compiled in table 1 and the variation of the proportions of some sections of the genitalia is compiled in table 2.

Remarks. M. kuznetsovi diOEers from M. roseni (Hesse) in the lower epiphallus: penis, ¯agellum and appendicula ratios (see table 2). The two species can hardly be distinguished by shell characters. The shell of M. kuznetsovi is light corneous, whereas the shell of M. roseni is usually whitish, and the umbilicus of M. kuznetsovi is on average slightly narrower than that of M. roseni .

M. kuznetsovi is di cult to distinguish from the sympatric M. (Metatheba) subcarthusiana . In M. subcarthusiana the shell is usually whitish, whereas it is light corneous in M. kuznetsovi and the umbilicus of M. subcarthusiana is usually wider than that of M. kuznetsovi . However, these diOEerences are probably insu cient for reliable determinations.

Etymology. This species is named in honour of Dr Andrey G. Kuznetsov, Moscow, who discovered it.

Type locality. Russia: SW slope of the Markotkh Gora NE of Gelendzhik, DK23 .

Distribution and material (®gure 17). M. kuznetsovi is known only from the type locality, but is probably more widespread in the westernmost foot-hills of the Caucasus.

Russia. SW slope of the Markotkh Gora NE of Gelendzhik, DK23 (det. anat.; holotype ZMH 2767 , leg. A. G. Kuznetsov 17 October 1992, measurements: D 5 12.6 mm, H5 9.2 mm; ZMH 2768 ) .