From editor or global species database
Type species The type species is Trypanosyllis krohnii. This has always been true as it is a type by monotypy, and thus no other possible candidate for type exists, and a subsequent designation from all originally included species (one) as an act proposed in Álvarez-Campos et al (2017) is clearly not needed and is illogical. It is not possible for T. zebra for example to be considered as the type species, but nevertheless its name may appear as type in loose usages in past literature simply because it was then the senior synonym of T. krohnii, and the two entities were thus not considered different. Álvarez-Campos, Giribet, San Martín, Rouse & Riesgo (2017: 492, 522) stated that they were newly clarifying the situation regarding T. zebra versus T. krohnii as type, because "Many years later Hartman (1959) designed [sic] Trypanosyllis zebra as the type species of the genus by subsequent designation (ICZN, article 69.1), and since then all the authors except Day (1967) considered this designation as valid [...] Our study found that Hartman’s designation is in fact not valid ...". However, Article 69 does not apply here. It is true that Hartman wrongly stated the type species, but the Hartman Catalogue cannot be considered as subsequently designating T. zebra as Trypanosyllis type species, because T. zebra was not an originally included species in the genus (Art. 68) and the type is already fixed by monotypy (Art. 68.3) to be T. krohnii. Day (1967) more exactly presented the type species as "Trypanosyllis krohnii Claparede, 1864 (= Syllis zebra Grube, 1860)". Other authors may have understood this coupling of the two names also but were less rigorous in their presentation, or they may have simply copied the type from Hartman's listing [G. Read, March, 2017] [details]
Type species Type species is Trypanosyllis krohnii Claparède, 1864, by monotypy. [details]