Halecium tensum Fraser, 1941b

Halecium tensum Fraser, 1941b: 84, pl. 17, figs. 11a–c.

Holotype. USNM 22926: USA, Massachusetts, off Martha’s Vineyard, R / V Fish Hawk Sta. 940, 39°54’N, 69°51’30”W, 245 m, 0 4 August 1881, trawl, one polysiphonic colony, ca. 5 cm high, in fair condition, without gonophores, labelled “ type ”; ethanol.

Type locality. USA, Massachusetts: off Martha’s Vineyard, 39°54’N, 69°51’30”W, 134 fm (245 m) (Fraser 1941b).

Current status. Valid.

Remarks. From the original description, Fraser (1941b) appears to have established Halecium tensum on the basis of a single colony. After examination and description, his “ type ” of the species was returned to collections at the NMNH (USNM 22926). The specimen count is correctly given as “1” in the online database of that museum, and no other type material is known to exist. While currently listed therein as a syntype, it is taken here to be the holotype by monotypy (ICZN Art. 73.1.2).

According to Fraser (1941b), this species somewhat resembles Halecium kuekenthali Marktanner- Turneretscher, 1895, it but differs in having a more rigid and less branched colony as well as longer internodes that lack annulations. Gonophores were lacking in the holotype, and the species has not been reported again. It is listed as valid in WoRMS.