Caucasocressa callosa Hausdorf and Falkner, 2001

Hausdorf, Bernhard, 2003, Revision of the genus Caucasocressa from the eastern Pontic Region (Gastropoda: Hygromiidae), Journal of Natural History 37 (21), pp. 2627-2646 : 2628-2632

Caucasocressa callosa Hausdorf and Falkner, 2001

(figures 2, 3)

Caucasocressa callosa Hausdorf and Falkner, 2001: 47 , pl. 6, figure 4. Type locality: ‘Vil. Artvin: above Demirkent , dry grassland, 2000–2300 m alt., GF32’, Turkey.

Shell (figure 3). Depressed conical; with 5.75 convex whorls; teleoconch with strong, wrinkled growth ridges; whitish, with a brownish band below the periphery and one above the periphery; body whorl rounded; aperture almost circular; upper insertion of the peristome usually slightly descending; peristome more or less sharp, not expanded, with a strong whitish internal rib with a callous thickening at the basal side; umbilicus moderately wide, taking about 15% of the shell breadth.

Measurements. Demirkent, 2000–2300 m alt. (N =4): D=9.6–11.0 mm, B = 10.5 mm; H=7.0– 7.8 mm, B = 7.5 mm; D/H=1.37–1.46, B =1.41.

Remarks. Caucasocressa callosa is characterized by the small, conical shell with a callous lip. Moreover, it differs from the neighbouring C. schmalzi in the narrower umbilicus. The genitalia of C. callosa are unknown.

Distribution and material (figure 2). Caucasocressa callosa is known only from the mountains near Demirkent.

Turkey: V . Artvin: above Demirkent , dry grassland, 2000–2300 m alt., GF32 (holotype ZMH 2884 ; paratypes ZMH 2885 ; FAL) .

F. 2. Distribution of Caucasocressa callosa Hausdorf and Falkner , Caucasocressa planospira Hausdorf and Falkner and Caucasocressa schmalzi Hausdorf and Falkner (l), Caucasocressa ibera , sp. n. (2), Caucasocressa joannis (Mortillet) ($), Caucasocressa menkhorsti , sp. n. (+), Caucasocressa phasiana , sp. n. (,), Caucasocressa taochorum , sp. n. (~), Caucasocressa tortumensis , sp. n. (&), Caucasocressa sp. (#) (UTM grid, 10 km squares).