(fig. 8G–I, table 2)
Opercularella pumila Clark, 1875: 61, pl. 9 figs 3–5; Calder, 1971: 65, pl. 4I.
Opercularella pumilla: Hargitt, 1909: 37.
Opercularella nana Hartlaub, 1897: 502, pl. 20 figs 9–11.
Campanulina pumila: Vervoort, 1946: 215, fig. 91; Cornelius, 1995a: 193, fig. 44; Schuchert, 2001a: 56, fig. 42A–B.
Material examined. Stn. ANI — 01.iv. 2005, 2 m, S24: a fertile colony, epizoic on Symplectoscyphus subdichotomus, 2 slides (MHNG INVE 53178).
Type locality. Portland (Maine) and off Montauk Point (Long Island), USA.
Description. Colonies minute, stolonal. Hydrothecae borne on spiral-twisted pedicels of variable length; long, tubular, distal 1/4 comprising membranous, conical, pleated operculum, composed of several triangular flaps, not distinctly delimited basally by crease-line; basal part gently tapering into pedicel and provided with thin diaphragm. Gonothecae arising directly from stolon; barrel-shaped but quite elongated; distal end truncated and provided with large, rounded aperture; gonotheca borne on short, twisted pedicel. Gonothecae empty.
Remarks. The present material is exclusively stolonal. Colonies composed of erect shoots of up to 5 hydrothecae were described from Great Britain (Cornelius 1995a). The hydranths in the present material were either retracted or badly preserved, so that the number or tentacles could not be checked. Cornelius (1995a) reported hydranths with ca 18 amphicoronate tentacles and having a minute, basal web. A thin diaphragm delimiting a basal chamber, similar to that observed by Schuchert (2001a) from Greenland material, is visible in some gonothecae from Chile.
World distribution. North Sea, North Atlantic, Pacific coasts of North America (Cornelius 1995a), Greenland (Schuchert 2001a).
Records from Chile. The present material was collected at only one station, from Angostura Inglesa, Canal Messier. This is the first record of the species for Chile.