(Fig. 2 C)
New locality. Rota, Provincia de Cádiz, Spain (36 ° 38 ’09”N, 6 ° 23 ’ 50 ”W). Los Corrales: thin layer of very coarse sand in intertidal pools on a rocky cape (11 /04/ 2008).
Known distribution. Northeast Atlantic: European Atlantic coast (Ax 1956; Ehlers & Sopott-Ehlers 1989); Bosporus and Sea of Marmara (Ax 1959); Mediterranean: Corsica and Sardinia (Willems 2005 and pers. comm. from Wim Willems).
Material. Several individuals studied alive. Five whole mounts.
Remarks. Animals are between 0.8– 2 mm (= 1.2 mm; n = 4) long. This species can easily be distinguished from other species of Promesostoma Graff, 1882 because the stylet is curled over 360 ° in the middle (Fig. 2 C). The stylet of the Spanish specimens is between 364–396 μm long (= 383 µm; n = 5), which is longer than in specimens from other known localities (± 250 µm in the specimens from the French Atlantic coast, Ax 1956; ± 290 µm in the specimens from Corsica, Willems 2005; no measurements given for the specimens from the Eastern Mediterranean, Ax 1959). Its new intermediate location in southern Spain suggests this animal is probably widespread throughout the Mediterranean and Atlantic coast of southwestern Europe.