TYPE MATERIAL Holotype (MNHN-IM-2000-34812) dim. 3.60 x 1.10 mm. Protoconch 0.40 × 0.27 mm. stn GS08. Paratype 1 (MNHN-IM-2000-34813) dim. 3.10 x 1.00 mm. Protoconch 0.40 × 0.27 mm. stn AB126. Paratype 2 (MNHN-IM-2000-34814) dim. 2.49 x 0.90 mm. Protoconch 0.38 0.28 mm. stn AB483.
TYPE LOCALITY Caribbean: Guadeloupe, Tête à l'Anglais, 23 m. DISTRIBUTION Guadeloupe, Martinique. MATERIAL EXAMINED Station of Guadeloupe: stn GS08, Tête à l'Anglais, 23 m, spm 1. Stations of Martinique: stn AB126, Pointe du Diamant, Anse Cafard, 3 m, spm 1; stn AB483, Vétiver, La Plate-Forme, 7 m, spm 1. DESCRIPTION Shell medium in size, conical, impressed sutures. Protoconch conical of 4.5 whorls with flat sides; under ESEM a thin spiral cord formed by granular microprotuberances becomes visible above the sutures; a narrow band of axial riblets is developed immediately below. Color yellowish, opaque. Teleoconch of 8 whorls with reticulate sculpture of 3 equal spiral cords crossed by axial ribs, about 16 on last whorl; beads at each intersection. A fourth beaded cord is emerging at the base of the last whorl from the insertion of the outer lip; border between columella and base highlighted by a cord. Columella short and broad, obliquely truncated, with a surface crossed by thin crisp threads, columellar callus bordering a oval aperture; anal sulcus and siphonal canal well defined. Semitransparent, background colorless, whitish beads, suture and 1st spiral cord yellowish; paratypes have more vivid color, yellowish becomes almost red brown.
COMPARISON Cerithiopsis brugneauxae n. sp. can be compared with the very variable Cerithiopsis albovittata (C. B. Adams, 1850); the main difference can be found in the shorter protoconch with impressed sutures and less numerous and coarser axial riblets.
ETYMOLOGY Named after Sophie Brugneaux, program officer at the Agence des Aires Marines Protégées (AAMP; now Agence Française de la Biodiversité, AFB) at the time of the MADIBENTHOS expedition. She played a key role in bringing various stakeholders around the MADIBENTHOS project.