Scyphoproctus Gravier, 1904

Silva, Camila Fernanda Da & Amaral, Antonia Cecilia Zacagnini, 2019, Scyphoproctus Gravier, 1904 (Annelida, Capitellidae): description of three new species and relocation of Heteromastides Augener, 1914 in Scyphoproctus, Zootaxa 4560 (1), pp. 95-120 : 98

Genus Scyphoproctus Gravier, 1904

Pulliella Fauvel, 1929 . Synonimized by Magalhães & Bailey-Brock (2012).

Heteromastides Augener, 1914 . Type-species: Heteromastides bifidus Augener, 1914 . syn. nov.

Type-species: Scyphoproctus djiboutiensis Gravier, 1904 . Type locality: Red Sea.

Diagnosis (emended after Magalhães & Bailey-Brock 2012). Rounded prostomium without palpode. Intersegmental groove between peristomium and achaetous segment may be complete or incomplete. Thorax with 11– 16 segments, including two achaetous segments (an achaetous peristomium and a following achaetous segment with lateral organs) and 9–14 chaetigers with capillary chaetae. Last thoracic chaetiger may have capillary notochaetae and hooded neurohooks or capillary chaetae only in both rami. Abdomen with hooded hooks throughout or with one or more pre-anal segments with acicular spines in the notopodia. Pygidium expanded as a poorly or well-developed anal plaque with a pair of ventral digitiform cirri; with or without a median membrane. Anal plaque with embedded or protruding acicular spines.

Remarks. All Scyphoproctus species have a rounded prostomium, generally thin, lack palpode, and the intersegmental division between peristomium and achaetous segment may be complete or incomplete; when it is incomplete, the delimitation between both segments may not be conspicuous leading to a confusion on the counting of the thoracic segments in Scyphoproctus specimens. The anal plaque may or may not present a median membrane between the anal cirri, which is taxonomic important because its shape, length and width are variable.

Magalhães & Blake (2017) discussed about the possibility that Leiocapitellides Hartmann-Schröder, 1960 and Heteromastides Augener, 1914 could actually belong to Scyphoproctus . After a revision of the holotype of H. platyproctus Pillai, 1961 (BMNH 1960.3.13.22) it was possible to conclude that it belongs to the current definition of Scyphoproctus . Heteromastides platyproctus presents a rounded prostomium without palpode, a well-developed anal plaque formed by the fusion of 10 chaetigers, and an achaetous segment, unnoticed by the author probably due to the conservation state of the specimens.

Among Scyphoproctus species there is already one named S. platyproctus Jones, 1961 . According to ICZN (1999), two or more congeneric species are not allowed to be under the same epithet, therefore, S. platyproctus Jones, 1961 should be considered the senior homonym (date of publication). We renamed the species Heteromastides platyproctus Pillai, 1961 as Scyphoproctus telesphorei n. nov. after the species author Telesphore Gottfried Pillai.

The type material of Heteromastides bifidus Augener, 1914 , type-species of the genus, could not be examined; however, according to the discussion of Pillai (1961), the only two differences between both species are that the anal plaque of H. bifidus lacks acicular spines (or they may not be protruding) and bears two anal cirri “arising from a common pedicle”, probably meaning that the anal plaque presents a median membrane between both cirri; confirming that it is also a Scyphoproctus species.