Dizoniopsis Sacco, 1895 (type species Cerilhium bilineatum Hörnes, 1855, type locality the Tertiary formations of Piemont) was created for fossil shells with only 2 beaded spiral cords on teleoconch whorls, but the original description did not mention protoconch, and the figure does not show it. Some authors have assigned to this genus shells with smooth protoconchs (Gougerot & Le Renard). But the genus was redefined by Nordsieck, (1968), the type of the genus having, according to him, a protoconch with a smooth first whorl, and following whorls with axial riblets extending from suture to suture. This genus was used by Glibert (1973) for shells with pupoid shape, with 2 beaded cords on teleoconch whorls, and protoconchs with axial ribs.

Among European cerithiopsids, a noteworthy and easily recognized morphological group is composed by species in which the teleoconch sculpture is composed of only two rows of beads until at least the penultimate whorl. In most of the other Mediterranean species of the family there are two (rarely three) cords on the first teleoconch whorl and a third one is added very early adapically along the suture.
SACCO (1895) introduced Dizoniopsis as a subgenus of Cerithiopsis, for Neogene fossils which were said to differ by having two rows of granules per whorl only. This character is shared by some Recent Mediterranean representatives, for which the name of the Miocene type species has been repeatedly used. There are two clearly different Recent species, long recognized by Mediterranean authors, but much confusion has arisen regarding which name should be used for one or another of them.

Type species: Cerithium bilineatum Homes, 1855, type locality Tertiary banks of Piemont: teleoconch with 2 beaded spiral cords per whorl, protoconch bearing axial ribs, extending from suture to suture, with smooth intervals (Dizoniopsis ss). We provisonally consider as Dizoniopsis (si) the species with 2 spiral beaded cords per teleoconch whorl, with protoconchs bearing spiral cords in intervals between the ribs (type 3) or with axial ribs that do not reach the upper suture (type 4).