Protoconch smooth, shiny, with 1,0 whorl. Transition to teleoconch marked by a slight depression and onset of axial and spiral sculptures. Teleoconch of up to 6 rounded whorls. Shoulder small, rounded, sloping back to an impressed suture forming a narrow channel. Axial sculpture of about 14— 16 low axial ribs on body whorl of adult; slightly more on earlier whorls. Ribs rounded in profile and narrower than intervening spaces. Periodic internal varices (see Harasewych and Petit, 1982: 111), noticeable on outer surface of shell as thickened axial ribs, each followed by a relatively flat area. Spiral sculpture of strong, broad cords (16-20 on body whorl. 6-7 on penultimate whorl); those on shoulder crowded, others usually with a secondary cord in the interspaces and rarely a tertiary cord. Aperture large with a widely elliptical, prosocline outer lip. Outer lip with a finely serrated edge; inner surface with 14 spiral lirae that diminish about a quarter whorl into the aperture. Columella with 3 folds, the posterior one being slightly larger and the anterior one forming the edge of the short, narrow canal. The anterior fold extends to the edge of the inductural callus with smaller fold-like features or pustules sometimes present on outer edge of inductura. Color yellow-brown with a dark red-brown band at shoulder and smaller lines or bands on body whorl. A white band is sometimes present just anterior to the shoulder and just anterior to the periphery.

Merica marisca has many features in common with the Philippine Merica ektyphos Petit and Harasewych, 2000, which has stronger sculpture with heavy nodes formed at intersections of spiral cords and axial ribs. In addition, M. ektyphos has a rounded and more solid shell, and the protoconch is 1/4 whorl larger than in M. marisca. Species of Merica five subtidally and on the continental shelf. The bathyal M. marisca is apparently the deepest living species in the genus.

Type Material: Holotype (25.7 mm height X 18.0 mm width)
Type Locality: Off northeast coast of New Caledonia, Passe de Hienghene, 20°34; S, 164°58' E, 470-490 m [BATHUS 4 sta. CP947].