Polysiphonia macrocarpa Harvey, 1836: 206–207, nom. illeg. (syntype localities: Port-Stewart, Londonderry, Northern Ireland; Miltown Malbay, County Clare, Ireland).—Untawale, Dhargalkar, & Agadi, 1983: .— Untawale, Reddy, & Deshmukhe, 1989: table 1.
Polysiphonia atlantica Kapraun & J. Norris, 1982: 226.
INDIAN OCEAN DISTRIBUTION: India.
Note: Polysiphonia atlantica is a substitute name for P. macrocarpa Harvey, a later homonym of P. macrocarpa (C. Agardh) Sprengel (1827: 350) (Hutchinsia macrocarpa C. Agardh, 1824: 157; type locality: "In mari Antillarum ad `Port au Pray''' [probably Port-de-Paix, Haiti]). The latter name is of uncertain application. J. Agardh (1863 [1851–1863]: 1061) thought that it applied to an alga similar to P. gaudichaudii (C. Agardh) Kützing (1843b: 422) (Hutchinsia gaudichaudii C. Agardh, 1828: 61–62; type locality: Cape of Good Hope, South Africa) or to P. virgata (C. Agardh) Sprengel (1827: 350) (Hutchinsia virgata C. Agardh, 1824: 157; type locality: Cape of Good Hope, South Africa). Papenfuss (notes) examined the type of H. gaudichaudii and concluded that it was referable to P. virgata (treated as a nomenclatural synonym of Carradoriella virgata (C. Agardh) P. Silva, comb. nov. on page 478 of this catalogue).