Volume 33

In terrestrial pulmonate gastropods Cochlodina laminata, Monachoides incarnata, Helicigona lapicida, Arianta arbustorum, Cepaea hortensis, Trochulus hispidus and Succinea putris, the morphological properties of the pupil of camera-like eyes were studied for the first time: location, spatial orientation, change in spatial orientation, structure, shape, shape change, relative size, change in relative size. Several methods were used in the work: making of preparations of isolated eyes, making of histological preparations of eyes, light microscopy, morphometric analysis, statistical analysis, calculations. All the studied morphological properties of the pupil of the camera-like eyes of C. laminata, M. incarnata, H. lapicida, A. arbustorum, C. hortensis and T. hispidus are similar to the analogous morphological properties of the pupil of the camera-like eyes of other species of terrestrial pulmonates. One of the studied morphological properties of the pupil of the camera-like eye of S. putris – the relative size – differs from the analogous morphological property of the pupil of the camera-like eyes of other species of terrestrial pulmonates.

The article reports the finding of a population of freshwater snails morphologically and genetically identified as Ladislavella cf. terebra (Westerlund, 1885), in a reservoir situated in Penza City. This is the first reliable record of representatives of the genus Ladislavella on the territory of European Russia, at a considerable distance from the previously known boundaries of its range. Molecular data suggest that the examined population belongs to the previously unknown species of Ladislavella. The morphoanatomic and ecological characteristics of the studied population and some information about parasites and commensals of mollusсs are given.

This study examines and provides illustrations of the diagnostic shell characteristics of juvenile and adult of Crimean clausiliids Balea perversa. The study demonstrates that the distinctive sculpture and shape of the shells make it possible to accurately differentiate Balea perversa. Additionally, the study includes information on previous references in the literature and recent findings of Balea perversa in the Crimea region, including a discovery on the Southern Demerdzhi Yayla in 2002. The study confirms the reliability of at least the last finding.

Chicomurex kozlovi sp. nov., collected from the Saya de Malha Bank in the Mascarene Plateau, Western Indian Ocean, is described and illustrated. The holotype was sampled at a depth of 200 m during the expedition of R/V Gordy in 1989, while paratypes 1 and 2 were trawled from a depth of 100-200 m by research-fishery boats during the eighties. Chicomurex kozlovi sp. nov. is compared with morphologically similar congeneric species.

The taxonomic and biogeographical composition of gastropod molluscs in the antique part of the fund collection of the State Historical and Archaeological museum-preserve Tauric Chersonese was diagnosed and analyzed. The complex of molluscs includes species from the Black Sea, Mediterranean, and Indo-Pacific groups. The shells of the European horn of Triton Charonia seguenzae were found only in Chersonese. To establish probable trade links between Chersonese and the Scythian-Sarmatian and Goth-Alanian worlds, the studied mollusc complex has been compared with archaeological finds in the Crimea and beyond. The biogeographical composition of mollusc complexes from the archaeological layers of Chersonese and "barbarian" necropolises has been shown to be identical, indicating the unity of the sources and the import route of shells.