Ophiodes carchesium Fraser, 1914b

Calder, Dale R. & Choong, Henry H. C., 2018, Names of hydroids (Cnidaria, Hydrozoa) established by Charles McLean Fraser (1872 - 1946), excluding those from Allan Hancock Expeditions, Zootaxa 4487 (1), pp. 1-83 : 35-36

Ophiodes carchesium Fraser, 1914b

Ophiodes carchesium Fraser, 1914b: 220 , figs. 1a, b.

Ophiodissa carchesium .— Fraser, 1937a: 113, pl. 23, figs. 127a, b.

Hydrodendron carchesium .— Rees & Vervoort, 1987: 21.

Holotype. BCPM 976-00508-001: USA, Alaska, Gulf of Alaska, SE of Trinity Islands, halibut grounds, 50 fm (91 m), 20 August 1914, on a bryozoan, one colony, in poor condition, without gonophores, coll. Dr. A. Willey; slide.

Type locality. USA, Alaska: Gulf of Alaska, SE of Trinity Islands, halibut grounds, 50 fm (91 m) ( Fraser 1914b).

Current status. Valid, as Hydrodendron carchesium ( Fraser, 1914b) .

Remarks. The hydroid briefly described as Ophiodes carchesium by Fraser (1914b) was found in a small collection from halibut grounds in the Gulf of Alaska, provided by Dr. Arthur Willey of McGill University, Montreal, Canada. The specimen, sterile and simple in morphology, was growing as an epizoite on a bryozoan colony. Material in the Fraser Hydroid Collection at the RBCM (BCPM 976-00508-001), comprising a single colony consistent with both the descriptive account and illustration in Fraser (1914b: figs. 1a, b), is considered by us to be the holotype by monotypy (ICZN Art. 73.1.2). The specimen and its bryozoan substrate have now slipped beyond the coverslip of the slide, but are still embedded in Canada balsam.

Known only from the original account, the species is listed as Hydrodendron carchesium in Rees & Vervoort (1987) , Cairns et al. (2002), and WoRMS. The specific name carchesium is a noun in apposition (Latin: a kind of drinking cup) and need not agree in gender with any generic name with which it is combined (ICZN Art. 31.2.1).

The family Phylactothecidae Stechow, 1921a is recognized here as valid following Choong et al. (2018). Included within it are H. carchesium and other species of the genus Hydrodendron Hincks, 1874 .