Ectocarpus elachistaeformis Heydrich, 1892: 470–471, pl. XXV: fig. 14 (type locality: Hatzfeldthaven, Papua New Guinea).—Misra, 1966b: 77–78, fig. 32.— Misra, 1967: 232.— V. Krishnamurthy & H. Joshi, 1970: 9.— Untawale, Dhargalkar, & Agadi, 1983: [17].— Wynne, 1995: 322–323, fig. 83.
Feldmannia elachistaeformis (Heydrich) Pham-Hoàng Hô, 1969: 299–301, fig. 3.3.—Islam, 1974b: 85.— Islam, 1976: 32–33, pl. 20: figs. 137–140; pl. 33: figs. 213, 214.— Ballesteros, 1994: 543.
Kuetzingiella elachistaeformis (Heydrich) M. Balakrishnan & Kinkar, 1981: 25–26, figs. 20, 98–100 (including Indian Ocean record).—Untawale, Dhargalkar, & Agadi, 1983: [19].— M. Balakrishnan & Kinkar, 1985a: 61, figs. 26–30.
INDIAN OCEAN DISTRIBUTION: Bangladesh, India, Mauritius, Seychelles (Mahé Island).
Note: According to M. Balakrishnan & Kinkar (1981; 1985), Kuetzingiella elachistaeformis lacks hairs and has discoid plastids and a chromosome count of n=9, characters that rule out assignment to Ectocarpus or Feldmannia. Amsler (in Schneider & Searles, 1991: 115), in retaining the species in Ectocarpus, stated that the plastids in North Carolina material are band-shaped. It is possible that reports of this species represent more than one taxon.