On the taxonomy of Recent Mediterranean species of the subgenus Loxostoma of the genus Rissoa (Mollusca, Gastropoda, Prosobranchia)

The taxonomical consequences of the presence of two types of apices among species of Loxostoma Bivona, 1838, are discussed. L. denticulus Bivona, 1838, is designated type species of Loxostoma. Neotypes of Rissoa monodonta Philippi, 1836, and of L. denticulus are designated, so that the latter becomes a junior objective synonym of the former. A lectotype of Rissoa auriformis Pallary, 1904, is designated. R. auriformis pseudomonodonta ssp. n. is introduced on the basis of two populations from the eastern Mediterranean (Greece).