Indian Ocean Catalogue


Carradoriella P. Silva, nom. nov. Carradoria Kylin (1956: 494, 503), non Carradoria Martius (1833: 15). Type species: Carradoriella virgata (C. Agardh). P. Silva, comb. nov. (Hutchinsia virgata C. Agardh, 1824: 157).

Carradoria is one of several genera segregated from Polysiphonia by Kylin (l.c.). Although he attributed the name to Martius, he effectively created a homonym in accordance with Art. 48.1 by excluding the type species. Carradoria Martius is an avowed substitute for Hutchinsia C. Agardh (1817: XXVI, 53), a later homonym of Hutchinsia R. Brown 1812 in the Cruciferae. The type species of both Hutchinsia C. Agardh and Carradoria Martius is Conferva fucoides Hudson, as I shall soon explain. This species is included in Kylin's circumscription of Polysiphonia.

Hutchinsia C. Agardh originally comprised 20 species without an indication of type. The homonymy with Hutchinsia R. Brown was soon appreciated and several substitute names were proposed independently. The relationship between the type of a replaced unavailable name (such as a later homonym) and that of the replacement was first specified by the Paris Code (1956), wherein Art. 7, Note 4, states that ``the type of the old name is automatically that of the new one''. This ambiguous wording is clearer in the French version, which reads ``le type du nom ancien devient automatiquement celui du nom nouveau''. Further clarification was made in the Montreal Code (1961) and retained in the Tokyo Code as Art. 7.3, which states that a nomen novum ``is typified by the type of the older name''. Nothing is said about the case in which the replaced name was untypified at the time the replacement was proposed. The wording is of little practical significance if the replaced name is unavailable, as in the case of Hutchinsia C. Agardh, but nonetheless it affects the disposition of synonyms. Assuming that the relationship given in Art. 7.3 is reciprocal, the type of Hutchinsia is that of its legitimate replacement, Grammita Bonnemaison (1822: 186), for which Conferva fucoides Hudson (1762: 485; type locality: Yorkshire, England) was named type.

Although ``Conferva Fucoides. Dillw. t. 75'' was cited by C. Agardh (1817: 54) as a synonym of H. violacea (Roth) C. Agardh (Ceramium violaceum Roth, 1797: 150--151, pl. VIII: fig. 2; type locality: Eckwarden, Oldenburg, Germany), it nonetheless can serve as the type of Hutchinsia in accordance with Art. 10, which does not require that the name of the type species be accepted by the author of the generic name. The correct citation in Hutchinsia is H. fucoides (Hudson) W. Hooker (1821: 87). It is an accepted species, Polysiphonia fucoides (Hudson) Greville (1824: 308), in the British flora (Maggs & Hommersand, 1993: 338).

Other names proposed as replacements for Hutchinsia C. Agardh are Polysiphonia Greville (1823 [1823--1824]: pl. 90), Girodia T. Lestiboudois (1827: 14), Grammalia Dumortier (1829: 76), Carradoria Martius (l.c.), Polyochetum Chevallier (1836: 678), and Polyostea Donati ex Ruprecht (1850: 39). For none of these names was a type indicated at the time of its proposal, but all are typified with Hutchinsia fucoides, the type of the replaced generic name.

Without regarding the nomenclatural history of Polysiphonia, Schmitz (1889: 448) designated P. violacea (Roth) Sprengel (1827: 348) as lectotype. Making two incorrect assumptions---first, that Polysiphonia was originally proposed by Greville in his Flora edinensis (1824), and second, that only a species mentioned in the original treatment of Polysiphonia could serve as lectotype---I relectotypified the generic name with P. urceolata (Lightfoot ex Dillwyn) Greville (1824: 309) (Conferva urceolata Lightfoot ex Dillwyn, 1809 [1802--1809]: 82, suppl. pl. G; syntype localities: various in England) when proposing it for conservation against Grammita Bonnemaison 1822 and Grateloupella Bory de Saint-Vincent 1823 (P. Silva, 1952a: 268, 293). (Polysiphonia had previously been conserved against the earlier taxonomic synonym Vertebrata S. Gray 1821, but its type species had not been specified.) In the list of conserved generic names appended to the ICBN, Polysiphonia urceolata has been cited as the type of the generic name beginning with the Paris Code (1956). It is a conserved type since in the absence of conservation the type would be P. fucoides. Maggs & Hommersand (1993: 355--358) placed P. urceolata in the synonymy of P. stricta (Dillwyn) Greville (1824: 309) (Conferva stricta Mertens ex Dillwyn, 1804 [1802--1809]: pl. 40; lectotype locality: Swansea, Glamorgan, Wales fide Maggs & Hommersand, l.c.).