Silicularia ? bilabiata (Coughtrey, 1875)

(Fig. 1 K, L, Table 2)

Campanularia bilabiata Coughtrey, 1875: 291, pl. 20 Figs 46–49.

Silicularia rosea ― Galea et al., 2009: 18, Fig. 4 G–M (not S. rosea Meyen, 1834).

1. Some are listed in Galea (2007).

2. Differences related to the size and shape of the hydrotheca were emphasized.

Material examined. Corral, Chaihuin/Huiro, lat. -39.95000, long. -73.61667, 30.xi.2011, 8‒ 10 m, sample 58: small colony with immature, most probably female gonothecae. HF6, “Inio 5”, lat. -43.40000, long. -74.08333, 24.ii.2008, 8 m, sample A504: colony with incompletely formed female gonothecae, on seaweed (MHNG-INVE- 62833).

Remarks. A small colony (sample 58) with immature (likely female) gonothecae occurs in the present collection and corresponds in every respect to the material assigned earlier (Galea et al. 2009, MHNG-INVE- 62833) to S. rosea Meyen, 1834 . Both specimens exhibit laterally flattened hydrothecae with equally developed walls, and their gonothecae are comparatively wider with respect to those in the material described below, that we are now assigning to Meyen’s species. In spite of the opinion expressed by Vervoort & Watson (2003, p. 444), stating that “there are no reliable characters that separate Silicularia rosea Meyen, 1834 from Campanularia bilabiata Coughtrey, 1875 ”, the peculiar position of the hydrothecal rim (compare Fig. 1 K with 1M) and the comparatively broader gonothecae (compare Fig. 1 L to 1N; see Table 2) set the present material apart from the typical concept of S. rosea, as illustrated through the redescription of the type by Hartlaub (1905, p. 573, Fig. T1).

However, owing to the scarcity of specimens in hand, it is impossible to ascertain the degree of morphological variation of the hydrotheca, especially regarding the position of its aperture. Though all specimens inspected had the plane of the aperture perpendicular to the long axis of the theca, thus resembling to the original illustration provided by Coughtrey (1875, Pl. 20 Fig. 46), it was already shown (Hilgendorf 1898, Bale 1924) that it may be inclined to one side, exactly as in S. rosea . Since the present identification is provisional and not intended to clarify the taxonomy of this nominal species at this stage, it should be taken with care, pending the re-examination of the syntype of Campanularia bilabiata designated by Ralph (1956, p. 287).

The relationships between S. bilabiata and both Eucopella campanularia von Lendenfeld, 1883 and E. reticulata Hartlaub, 1905, all provided with broad, ovate, laterally flattened gonothecae, are unclear at present. Distribution in Chile. South of Chiloé (Galea et al. 2009), and Corral (present study).

World records. The lack of knowledge on the specific limitation of S. bilabiata prevents us from establishing an exhaustive list of distributional records.