Lithothamnion proliferum Foslie, 1904a: 18–19, fig. 8, pl. I: figs. 17–20 (`prolifer') (lectotype locality: Lumu-Lumu shoal [Pulau Lumulumu], Borneo Bank, Indonesia fide Verheij & Woelkerling, 1992: 282).—Vasseur, 1965: 30, 31, 33, 34, 35, 43, 53, 68.— Pichon, 1974: 302.— Untawale, Dhargalkar, & Agadi, 1983: [39].
INDIAN OCEAN DISTRIBUTION: India, Madagascar.
Note: Adey (1970: 25) transferred Lithothamnion proliferum to Mesophyllum but Verheij (1994: 120–121) advocated retaining it in Lithothamnion on the basis of epithallial and medullary anatomy. The species was based on collections from two Siboga Expedition stations on the Borneo Bank, 78 (Lumu-Lumu shoal) and 81 (Pulu Sebangkatan). Foslie (1904a: 18) did not indicate a type, but he stated that the species was best developed at station 81. In his pl. I, he showed two specimens (figs. 17, 18) from station 78 that he considered "not quite typical'' and two specimens (figs. 19, 20) from station 81 that he considered "typical''. Adey & Lebednik (1967: 67), in their catalogue of Foslie's herbarium (in TRH), designated the material from station 81 as the type collection, comprising specimens no. 971a and 971d. Adey (1970: 25), referring to these specimens as "co-types'', implied that because very little of 971d was extant, he had "isotyped'' 971a (Foslie, 1904a: pl. I: figs. 19, 20). While Adey's choice of words is unorthodox, it seems clear that he did not make a definite choice of lectotype between the two "co-types''. Verheij & Woelkerling (1992: 273–274) pointed out that the bulk of the Siboga Expedition nongeniculate collections, including type specimens, was returned to Weber-van Bosse (at L) by Foslie, who retained only fragments. They examined the syntype collections of Lithothamnion proliferum at L and found that only no. 146 from station 78 (Foslie, 1904a: pl. I: fig. 17) had multiporate conceptacles in agreement with Foslie's protologue. Therefore, they (op.cit.: 282) designated this collection as lectotype and thus overrode Foslie's statement that nos. 971a and 971d are "typical'' as well as Adey & Lebednik's designation of lectotype locality.