From the introduction: With the 11th volume, published about three years ago, we believed we had concluded our work, but the discovery of other new unpublished specimens inspired us to create this new volume which we hope will be appreciated like the previous ones. With the new 43 species threated we have reached a total of 1.293 growths.

We have also attended to a remarkable number of comparison tables (126) allowing us to conclude this new volume with a format absolutely similar to the previous ones. The comparison tables have always been appreciated since they are useful for the determination of species belonging to the same genus or family, so similar to each other. Some of these comparisons are of groups for which we were unable to photograph the growths of the single species for lack of material.

We also made again family comparisons already published in our previous volumes (i.e. Alvania) illustrating however the only species that in the systematic, always evolving quickly, have been added in the meantime. We have provided with a handy general reference index at the end of these tables. The remarkable taxonomic changes produced by genetic and molecular studies obliged us to make relative updates to the systematic which are numbered with several footnotes referencing the old taxonomy.

Then, where possible, there have been inserted growths of some new species recently described such as: Alvania villarii, Chileutomia raveggii, Calliostoma funiculatum, Draculamya carlosbranai, Ondina michaelae, Aphanitoma mariottinii, Mitromorpha mifsudi, Alvania rominae, Megastomia crovatoi…

Among the species that have been reported as new hosts in the Mediterranean Sea, we have illustrated, sometimes also with specimens coming from the areas of origin: Rugalucina angela, Planaxis savignyi, Mytilopsis sallei, Mytilopsis leucophaeata…

It has been furthermore set up a table with photos of species, adults only, belonging to Families composed of a single species. For these ones a short note is also enclosed (Note on unique species) where there are mentioned some morphological features of habitat and/or of distribution.

As per the other volumes there are listed all those, entities or natural persons, who in this last volume contributed, by lending photos and specimens, to the completion of the individual growths. A dutiful thanks to Daniela Marcucci who, as in all the previous volumes, provided us with the translation of this volume.

At the end of the volume, in addition to the standard species and comparison indexes, we have constructed indexes (species and comparisons) for everything published in the 12 volumes published from 2009 to the present. Naturally, the names are those in effect at the time of printing and therefore, due to the ongoing evolution of the systematics, may not coincide with the current names.

Languages: Italiano e Inglese

Edition: 2026