Calloplax vivipara (Plate 1899)

Animal of small size, up to 12 mm in examined specimens, elongate oval, moderately elevated, color of tegmentum tan or creamy white. Head valve semicircular, sculpture with about nine equally spaced, nodulose, annulate and well defined radial ribs. Intermediate valves rectangular, lateral areas well defined, sculptured with two strong radial ribs. Central area with about eight longitudinal riblets per side, well-marked in the pleural areas but becoming obsolete at the jugum. The riblets tend to converge anteriorly and are not latticed. Posterior valve semi-oval, elevated at the central mucro, with nine well defined radial ribs. Girdle yellowish white, dorsally covered with small scales (After Ferreira 1978).

Plate (1899) described this species for Isla Pacharos (=Pájaros), near Coquimbo, Chile (29°58’S; 71°21’W). Ferreira (1978) additionally recorded this species from the intertidal of Pozo Toyo, South of Iquique, Tarapacá Province (20°25’S; 70°10.5’W) and mainland East of Isla Santa María, North of Antofagasta, Antofagasta Province (23°25’S; 70°36’W) from specimens housed at the LACM. A specimen labelled Chiton janeirensis (NHMUK 197742) identified by Ferreira (1978) as Calloplax viviparus extended the southern distribution of this species at Valparaiso (33°02’S; 71°38’W). This is the first time this species is recorded, in the field, since its description and the present record fills a gap in the distribution in Chile of this rare species.