Shell cyrtoconoid, elongate, solid. Protoconch with almost 2 whorls, with a diameter of 260 µm, and a diameter of the nucleus of about 100 µm; the first whorl has a rough microsculpture while the second whorl has two not very prominent spiral cords. The teleoconch has about 6 whorls and presents spiral nodules at the crossing points of ribs and cords. On the second whorl the upper spiral cord shows that the nodules are bifurcating, which is more evident on the third whorl, both being clearly separated on the fourth and fifth whorls; on the last whorl the three cords are well separated and below them there are two more not nodulous cords towards the base; the suture is evident, but not deep. Aperture almost ovoid, with a short, open and slightly recurved siphonal canal. Columella with a reinforcement; slightly curved but straight in the lower part. The colour of the shell is uniform light brown, the apex slightly lighter. Dimensions: the holotype is 2.57 mm long. All the material is of similar size.

Due to its similarity with Dizoniopsis apexclarus Rolan, 2007 it was considered to include the new species in this genus, but most of the whorls of the new species have three spiral cords, and so we prefer to keep it in Cerithiopsis sensu latu. Cerithiopsis inespazosae sp. nov. may be distinguished from Dizoniopsis apexclarus because the latter has a larger shell with more whorls, a darker brown colour, a narrower protoconch which is variable (studied and figured by Rolan, 2007), the microsculpture of the second whorl of the protoconch always has one spiral cord and numerous axial riblets, and the upper spiral cord of the teleoconch is not bifurcated on the entire shell. Both sympatrically occur in Minerio. Dizoniopsis bilineata (Hoernes, 1848) from the Mediterranean (protoconch shown in Giannuzzi-Savelli et al., 1999) has a protoconch with a more angulose first whorl, the second whorl with more prominent cords and the upper spiral cord not bifurcated down to the last whorl.

Only known from the type locality. Taken its short protoconch into account, it is probable this species is endemic to the island of Sao Tome. Type locality: Minerio, North of Sao Tome, 35-41 m, Republic of Sao Tome and Principe.