Type locality: Big Bay, Espiritu Santo, Vanuatu
Description Shell small, ovate (W/H 0.47, A/H 0.52), with short and stout siphonal canal, and finely gramulated sculpture. Protoconch missing. Teleoconch of ca 4% whorls; suture adpressed. First whorl nearly subcylindrical, later whorls with narrow subsutural ramp and gently convex periphery, widening towards lower suture. Sculpture of fine, rounded, orthocline ribs separated by equally broad interspaces, and intersected by regular cords, forming cancellate pattern with rounded beads at intersections. On later whorls cords becoming stronger and ribs weaker, vanishing entirely on last quarter of whorl. Penultimate whorl with 22 axial ribs and 5 cords. Last whorl evenly convex, with shell base gradually extending to short, blunt siphonal canal. Adapical portion of last whorl with 6 beaded cords, followed by 9 cords on shell base and siphonal canal; of these 9, only upper two cords somewhat gemmate. Aperture moderately wide; siphonal notch and apical callous pad not pronounced. Outer lip evenly convex, with wavy margin and 10 distinct lirae inside. Columella with four, fine, oblique folds gradually diminishing in size. Background color white, with contrasting light brown spiral band over two abapical cords on spire whorls (roughly% of whorl height), and over 4-6 cords on periphery of last whorl. Five cords on shell periphery with light brown crests. Radula minute; rachidian with rather broad base, and three broadly interspaced pointed cusps. Laterals sickle-shaped, with one long cusp. Etymology The species is named after our colleague, passionate malacologist Dr. Maria Vittoria Modica (SZN, Italy), in appreciation for her long time participation in field work and research with the extended MNHN team Distribution Known only from the type locality. Remarks This small species is readily distinguishable from other Costapex species, based on its ovate shell. regular cancellate-beaded sculpture, and the characteristic color pattern. The morphologically closest species, C. margaritatus, has stronger and fewer spiral cords, the dark blotches are irregular, and the 34 siphonal canal notably longer. The species of the C. sulcatus complex also have more elongate shells, and share a distinct subsutural band, which is not pronounced in C. mariavittoriae.