Volume 26

Eduard von Martens (1831–1904) was a prominent German malacologist of the nineteenth century contributed heavily to taxonomy and zoogeography of different groups of Mollusca and created a plethora of taxonomic names of the genus and species rank. The type materials of the species described by him are kept now in the Berlin Natural History Museum (Museum für Naturkunde). This article deals with von Martens’ role as a student of continental snails and bivalves of the former Russian Empire. Though von Martens did not travelled to Russia himself, he was able to study numerous samples of mollusks provided to him by both Russian and German explorers. It made him a great student of Russian malacofauna of that time. Most of von Martens works in this field were devoted to investigation of continental mollusks of the underexplored regions of the Russian Empire (Siberia, Russian Turkestan, Caucasus). At least 15 species described by von Martens are accepted as valid by the Russian malacologists. The article contains detailed accounts of the 15 species with illustrations of their type materials (lectotypes, syntypes), notes on distribution, taxonomy and nomenclature of these taxa.

Arion distinctus is reported from the urban biotope of Uzhorod. It is possible that the specimen from Uzhorod environs, early identified as Arion hortensis, belonged to A. distinctus. For the first time Arion circumscriptus is reported from the Eastern Ukraine (Donetsk Region). The external (coloration) and internal (genital structure) distinctions of these species are described.

Oxyloma sarsii tulomica subsp. nov. is described from the Kola Peninsula. The subspecies differs from the nominative subspecies Oxyloma sarsii sarsii, described from the Northern Norway in having predominately transverse folds in the inner penis wall, different shape of the crystals inside the penis. Data on variability and biology of the subspecies are presented, some problems of taxonomy of O. sarsii are discussed.

The species composition and quantitative distribution of freshwater gastropods in 26 water bodies of the Vishtynets upland (Kaliningrad region, Russia) are described. Samplings were made in 2013–2014. There were found 24 species of gastropods – 6 Prosobranchia and 18 Pulmonata. Most of obtained species are members of the permanent water body communites: Planorbarius corneus, Bithynia tentaculata, Lymnaea stagnalis, Viviparus contectus, Stagnicola corvus, Radix auricularia, Radix balthica, Planorbis planorbis, Physa fontinalis and Anisus vortex. Radix ampla, Ancylus fluviatilis and Aplexa hypnorum were found in the studied area for the first time. 14 species known from the literature inhabit the Vishtynets lake were absent in studied samples. The thanatocoenoses in the trout rivers with high speed current include freshwater gastropod shells that are typical for the stagnant water bodies. In studied samples some invasive species that were previously recorded for the adjacent areas of the Poland and the Kaliningrad region were absent. Five of recorded species are included in the Red Data Book of the Kaliningrad region.

Two species of South-East Asian genus Parmarion Fischer, 1856 (P. martensi Simroth, 1894 and P. pupillaris Humbert, 1864) (Ariophantidae) have been found in Central Vietnam (Dak Lak province). Illustrated descriptions of external appearance and reproductive tracts of both species are presented. Along with these species one juvenile specimen of Meghimatium bilineatum (Benson, 1842) (Philomycidae) has been found in south-east part of Vietnam (Dalat City).

The description of the new genus Antarctophiline gen. nov. with the type species Philine gibba is given based on penial and gizzard morphology. The new genus includes also A. alata and A. amoena. The anatomy of Antarctophiline gibba shows many similarities with “Philine” alba and “Philine“ alboides. The new genus definitely doesn’t belong to Philinidae s.str. It differs from Laonidae in lacking of gizzard plates and has some similarities with the family Philinorbidae. The new genus is tentatively placed into the family Philinorbidae. Features of morphology of Antarctophiline gibba described from different localities are discussed.

The polyplacophoran genus Hanleya contains two similar species in the Northeast Atlantic, H. hanleyi (Bean in Thorpe, 1844) and H. nagelfar (Lovén, 1846), which were primarily differentiated by dramatic difference in size but also in part by distribution and minor morphological and ecological features. The question of whether these two names represent two species or whether H. nagelfar is merely a name for H. hanleyi that have grown to extraordinary size, has been raised repeatedly since 1865. The problem was protracted by inaccessibility of the type specimen for the senior species name, and a lack of material collected near the type locality of H. hanleyi, both issues which we resolved in the course of this study. We examined the details of valves, girdle armature, and radula in specimens of Hanleya hanleyi from the Mediterranean Sea and Scotland. The similarity of relevant features among small specimens of H. hanleyi and H. nagelfar from Scotland, the Mediterranean Sea, Norway and Newfoundland Bank and the type specimen of Hanleya hanleyi suggests the two species are synonymous. Hanleya nagelfar is a junior synonym of H. hanleyi. Finally we note the eggs of H. hanleyi contain an unusual large drop of lipid that may increase their floatation. We propose that the eggs and larvae of H. hanleyi have an extended pelagic distribution and this extended dispersal period may connect populations from bathyal habitats in the slope of Newfoundland Bank via surface currents of the Gulf Stream System to northward and eastward in the Atlantic ocean.

The validity of Astarte inaequilatera (Filatova in Scarlato, 1981) (Bivalvia: Astartidae) is substantiated. It is a Pacific, widely-distributed boreal species, earlier synonymized with the subtropical, Japanese-Korean Astarte hakodatensis Yokoyama, 1920. A. hakodatensis differs from A. inaequilatera by the crenulated inner ventral margin of the shell, lack of undulating commarginal ribs (only growth marks are present), radial threads, and strongly produced anterior margin. The shell is thicker and darker, with a dark brown periostracum. A. inaequilatera usually has a yellow-brownish to olivaceous periostracum. A. hakodatensis differs from Astarte montagui (Dillwyn, 1817) by the crenulation of the inner margin and a smaller size. Detailed synonymies of both species are compiled for the first time. Taxonomic and faunal comments on the Astartidae of the Russian Far Eastern seas are provided.

The genus Retimohnia McLean, 1995 is revised based on conchology, radular morphology, foregut and stomach anatomy. Ten previously described species are recognized as valid: R. frielei (Dall, 1891), R. bella (Ozaki, 1958), R. vernalis (Dall, 1913), R. clarki (Dall, 1907), R.hondoensis (Dall, 1913), R.micra (Dall, 1907), R. sordida (Dall, 1907) comb. nov., R. robusta (Dall, 1913), R. caelata (Verrill et Smith, 1880), R. acadiana García, 2008. two species are described as new: R. lussae sp. nov, and R. mcleani sp. nov. R.japonica (Dall, 1913) is reduced to a junior synonym of R. micra, R. clementina (Dall, 1919) considered as a junior synonym of R clarki. Five species are excluded from the genus. Lectotypes designated for Mohnia frielei, Mohnia vernalis, Mohnia sordida, Mohnia clarki.

Five new species of Olivoidea are described based on molecular and morphological evidence: four shallow subtidal Ancilla from Madagascar and Papua New Guinea, and one deep water (500-600 m) Calyptoliva from the Tuamotus. The sympatric – but not syntopic - Ancilla morrisoni and A. kaviengensis, from New Ireland province, are morphologically cryptic, differing mostly in shell colour, but are molecularly distinct. The sympatric – and possibly syntopic - Ancilla atimovatae and A. lhaumeti, belong to a species flock from southernmost Madagascar;  A. atimovatae is conchologically nearly indistinguishable from A. ventricosa, but differs markedly in radular morphology. Calyptoliva was previously known only from the Coral Sea; C. bbugeae is the first representative of the genus to yield molecular data. The new Ancilla are described based on sequenced holotypes; the type material of the new Calyptoliva includes a sequenced paratype.