Morphological and molecular evidence support the intertidal barnacle Nilsson-Cantell, 1921 (Thoracica, Chthamalidae) as a valid species in Indo-Pacific waters.

is a chthamalid intertidal barnacle with eight shell plates. There are currently two species of such barnacles: Darwin, 1854 (type locality in the Philippines), common in the Indo-Pacific region, and Sowerby, 1825, only recorded in South Africa. Nilsson-Cantell, 1921, identified from the Mergui Archipelago in Myanmar, was considered to be conspecific with by Hiro (1939) based on samples collected in Taiwan.