Note: The name Dermocarpellaceae was proposed informally by Ginsburg-Ardré (1966: 364) and formally by Christensen (1978: 66) to apply to the family previously called Dermocarpaceae. This action was necessary in view of the demonstration by J. Feldmann & G. Feldmann (1953) of vegetative cell divisions in the type species of Dermocarpa. The names Dermocarpa and Dermocarpaceae were thus removed from the present family, which is characterized by lack of vegetative cell divisions. The family name Dermocarpellaceae is based on Dermocarpella Lemmermann (1907: 349), a genus that differs from Sphaenosiphon only in that the contents of each heteropolar cell undergo one or more horizontal divisions before conversion of the resulting segments into nanocytes.
Note: As a consequence of the demonstration by J. Feldmann & G. Feldmann (1953) of vegetative cell divisions in the type species of Dermocarpa, those species that had been assigned to Dermocarpa but whose sole mode of cell division is the production of endospores (nanocytes sensu Komárek & Anagnostidis, 1986: 168) must receive another generic name. Geitler (1967: 411) considered the oldest available name to be Cyanocystis Borzì (1882: 314), whose type species, C. versicolor Borzì, is congeneric with those species misplaced in Dermocarpa. Subsequently, numerous combinations have been made under the generic name Cyanocystis. However, there is clearly an earlier available name, Sphaenosiphon Reinsch (1875: 15), all but one of the ten original species having been transferred to Dermocarpa at one time or another. Drouet & Daily (1956: 101) chose S. cuspidatus Reinsch as the lectotype species, and after examining the type specimen (in K, now in BM) they assigned it to Entophysalis conferta (Kützing) Drouet & Daily. The choice of S. cuspidatus as lectotype species was very likely based on the fact that this species was the first of the ten species treated by Reinsch rather than that it best fit the generic diagnosis. In fact, although Reinsch specified in his generic diagnosis that the contents of the cells divide into numerous small spheres ("Zoogonidia?'', i.e., endospores or nanocytes), such spheres are neither mentioned nor figured for S. cuspidatus. Thus, this lectotypification should be overturned in accordance with Art. 10.5 in favor of S. olivaceus Reinsch, for which nanocytes are both mentioned and figured.
Dermocarpa hemisphaerica Setchell & Gardner in Gardner, 1918a: 438–439, pl. 37: fig. 21 (type locality: Moss Beach, San Mateo County, California, U.S.A.).—Iyengar & Desikachary, 1944: 41–42, fig. 5.— Venkataraman, 1958: 472.— Desikachary, 1959: 173, pl. 33: figs. 11, 12.— Basson, 1979: 63, pl. VII: fig. 38.— Farghaly, 1980: 134.— G. Subramanian et al., 1989: 318.— Thajuddin & G. Subramanian, 1992a: table III.
Sphaenosiphon hemisphaericus (Setchell & Gardner) P. Silva.
INDIAN OCEAN DISTRIBUTION: India, Madagascar, Saudi Arabia.
Note: Drouet & Daily (1956: 112, 117), after examining the holotype of this species (in UC), assigned it to Entophysalis conferta (Kützing) Drouet & Daily. Assignment of this species to Dermocarpella was suggested by Ginsburg-Ardré (1966: 365) after examining material determined by Gardner (Collins, Holden, & Setchell, 1895–1919, no. 2253), but not the type collection. An examination of the type collection at Berkeley (UC 205696) reveals that it comprises filaments of Rhodochorton purpureum (Lightfoot) Rosenvinge on which are growing representatives of three species described by Setchell & Gardner in the same paper. Dermocarpa hemisphaerica and D. suffulta are accurately described and figured. The former is clearly referable to Sphaenosiphon while the latter, which has a distinct stalk, is referable to Dermocarpella sensu J. Feldmann & G. Feldmann (1953), its correct name being Chamaecalyx suffultus (Setchell & Gardner) Komárek & Anagnostidis (1986: 199).