Onoba oliverioi n. sp. (Prosobranchia, Rissoidae), a new gastropod from the Mediterranean

Onoba oliverioi n. sp. (Prosobranchia, Rissoidae) is here described from material collected on muddy bathyal bottoms surrounding a deep-sea coral bank located off-shore Latium (Central Tyrrhenian Sea). The new species is known from shells only and it has been placed in the genus Onoba H. and A. Adams, 1852. Onoba oliverioi n. sp. is compared to Onoba gianninii (Nordsieck, 1974) (deep-shelf), Onoba dimassai Amati and Nofroni, 1991 (shallow water) and Alvania wareni (Templado and Rolan, 1986) (deep-shelf), which it resembles. A list of mollusc species found associated with the new taxon is also given.