Halecium robustum Nutting, 1901a: 182, pl. 23, figs.3–5 [invalid junior primary homonym of Halecium robustum Verrill, 1873, and Halecium robustum Pieper, 1884, and Halecium robustum Αllman, 1888].
Halecium harrimani Nutting, 1901b: 789 [new replacement name for Halecium robustum Nutting, 1901a, not Halecium robustum Verrill, 1873].
Halecium crassicaule Fraser, 1947a: 273 [new replacement name for Halecium robustum Nutting, 1901a, not Halecium robustum Verrill, 1873].
Syntypes. USNM 71169: USA, Alaska, Harriman Alaska Expedition, Alexander Archipelago, Glacier Bay, Berg Inlet; ethanol.
USNM 70881: USA, Alaska, Alaska, Alexander Archipelago, Glacier Bay; ethanol.
Type locality. USA, Alaska: Glacier Bay, Berg Inlet (Nutting 1901a).
Current status. Invalid.
Remarks. Fraser (1944a: 201) recognized that the name Halecium robustum Nutting, 1901a was preoccupied by several other binomena, including H. robustum Verrill, 1873. Unaware that Nutting (1901b) had already discovered the homonymy and provided H. harrimani as a new replacement name for his H. robustum, Fraser (1947a: 273) proposed H. crassicaule as a nomen novum for the same taxon. As a junior objective synonym of Nutting’s H. robustum and H. harrimani, Fraser’s H. crassicaule has the same name-bearing types (ICZN Art. 72.7). The name H. harrimani is now taken to be the valid name of the species (Calder 2004; WoRMS).
Two collections of Halecium robustum Nutting, 1901a (= H. harrimani) from Glacier Bay, Alaska, are listed in the online database of the NMNH. Only one of them is listed as syntype material (USNM 71169). The second (USNM 70881), having similar collection data, has not been included as a name-bearing type. It, too, is regarded here as part of the syntype series. No other type material of the species is known to exist. From published records, H. harrimani is presently known only from the type locality (Fraser 1947a).