Volume 21

Shells of one of Physa Draparnaud, 1801 species, inhabiting the rivers and reservoirs of the North Azov Sea coast clearly fit the re-description and figures of North American Physa skinneri Taylor, 1954. The illustrated description of the species from Ukrainian populations is provided here; some data on its distribution in Ukraine and in entire Eurasia are discussed. It is quite possible that these Eurasian conchological «twin» for Ph. skinneri should be attributed to one of the Old World aborigine species. To solve this problem the type materials for most common European Physa species, as well as their variability, anatomy and other characteristics should be studied.

In June 2010 the new to the fauna of Belarus land snail species Brephulopsis cylindrica had been found. It is supposed that eventual way of penetration of this species is casual importing by railway transport. At present this population existing during some years.

Morphology of the slugs, variability of their coloration, external structure of the distal parts of reproductive system, internal structure of the atrium and oviduct were studied. The considerable inter- and intrapopulation variability of the ligula was revealed. The structure of spermatophores and their parts, separate stages of the mating behaviour of the slugs were shown. Short description of the life cycle is given. Morphological, anatomical and behaviour peculiarities of the Western-Ukrainian slugs from the Arion lusitanicus complex  are compared with the published data for Great Britain, France, Belgium, Germany and Poland.

Among a small collection of Polyplacophora from the Hans-Georg Müller collection at the Bavarian State collection we recognized an undescribed species of Leptochiton Gray, 1847, which is described herein. The species is minute (2.1 mm) and shows a strong sculpturing of roundish granules, quincuncially arranged on the tegmentum. The species’ small size, long intersegmental spicules, and the high tail valve with a concave postmucronal slope, easily separates this species from its congeners. In addition, based on the new material, we are able to raise the number of chiton species identified in Sri Lanka to 24, although three of them require further study. The former known species are compiled to make an easy tracing of the Sri Lanka chiton fauna possible. Within this evaluation we transferred the species Tonicia pectinoides Sykes, 1903 and Tonicia ceylonica Leloup, 1936 to the genus Lucilina, following the concept of Schwabe et al., [2008]. Besides the new species, Rhyssoplax maldivensis (E. A. Smith in Gardiner, 1903) and Acanthochitona leopoldi (Leloup, 1933), were the first time mentioned from Sri Lanka. Comparisons with the chiton faunas of the Andaman Sea area and the Maldives show that minimal species overlapping occurs, despite a similar species numbers in the three areas discussed.

Minute turriform conoideans comprise a considerable fraction of the taxonomically undescribed diversity of marine mollusks. Species of the genus Lienardia, Jousseaume, 1884, extremely diverse in shallow water tropical marine communities, have long been overlooked by taxonomists and a high proportion of them remain undescribed to date. Development of a specialized collection technique, based on deployment of lumun-lumun nets have provided a vast amount of material on this group and enable several new species to be distinguished. Examination of material from the Philippines and other regions of tropical Indo-Pacific revealed five new species of the genus Lienardia, which are being described as L. acrolineata, L. grandiradula, L. multicolor, L. roseangulata and L. tagaroae. Examination of radulae in described species of the genus Lienardia shown unexpected morphologic diversity. It suggests that either rapid morphological specialization of Lienardia members had taken place in the evolution of the genus, or similarity of shells in Lienardia species is possibly convergent.