Wolfgang Zeidler

Validation of the replacement name Eusceliotes Stebbing, 1888 for the pelagic hyperiidean amphipod genus Euscelus Claus, 1879 (Crustacea: Amphipoda: Hyperiidea: Parascelidae), preoccupied by Euscelus Schoenherr, 1833 (Insecta: Coleoptera: Attelabidae)

The generic name Euscelus was originally proposed by Schoenherr (1833: 205) for a genus of Leaf Rolling weevils (Insecta: Coleoptera: Attelabidae). It is a valid name, in current use, for a relatively large genus of weevils, widespread in northern South America and central America, including the West Indies and the Caribbean (e.g. Hamilton 2007; Legalov 2007). Euscelus Claus, 1879 was established as a monotypic genus of pelagic amphipod (Crustacea: Amphipoda: Hyperiidea: Parascelidae). It is a very rare genus, still monotypic, with the only species, E. robustus Claus, 1879, having been recorded only twice in the literature prior to my review of the families and genera of the superfamily Platysceloidea (Zeidler 2016); initially by Claus (1879), from the Indian Ocean (off Zanzibar), and secondly by Spandl (1927), from the North Atlantic Ocean (off the Azores). Both authors only recorded males. While examining the collections of the Zoological Museum, University of Copenhagen (Zeidler 2016) more specimens of this rare species were located amongst the collections of the Dana expeditions of 1928-1930 (Jespersen & Tåning 1934), thus enabling a more complete description of the species including that of females. It was recently brought to my attention that, according to the data base Interim Register of Marine and Nonmarine Genera (Rees 2016), Euscelus Claus, 1879 is a junior homonym of Euscelus Schoenherr, 1833. While researching this problem I discovered that Stebbing (1888) had also become aware of this homonymy and had suggested the replacement name Eusceliotes. Unfortunately, Stebbing (1888) only refers to the name in his index (pp. 1672, 1699) and hence subsequent authors were unaware of the above homonymy and Stebbings replacement name, although it is listed by Neave (1939: 370). The purpose of this communication is to resolve the above homonymy by validating Stebbings (1888) replacement name. This action is preferred to proposing yet another new name for Euscelus Claus, 1879, in order to avoid further confusion, because Stebbings name, Eusceliotes, already exists in the literature (Stebbing 1888, Neave 1939).

Validation and redescription of the hyperiidean amphipod Brachyscelus rapacoides Stephensen, 1925 (Crustacea: Amphipoda: Hyperiidea: Brachyscelidae), a new record of association with the scyphozoan jellyfish Rhopilema nomadica Galil, 1990 (Scyphozoa: Rhizostomeae: Rhizostomatidae) in the Mediterranean Sea

The hyperiidean amphipod Brachyscelus rapacoides Stephensen, 1925 is recorded from the scyphozoan jellyfish Rhopilema nomadica Galil, 1990, a new record of association for the genus Brachyscelus, as well as the first record of hyperiid infestation of a non-indigenous scyphozoan host. Because of some past confusion concerning the status of B. rapacoides and the closely related species B. rapax (Claus, 1871) a redescription of B. rapacoides and molecular analysis are provided in order to validate it as a species distinguished from B. rapax.

A review of the families and genera of the superfamily PLATYSCELOIDEA Bowman & Gruner, 1973 (Crustacea: Amphipoda: Hyperiidea), together with keys to the families, genera and species

The systematics and phylogenetic relationships of the families and genera of the superfamily Platysceloidea are examined, following a thorough examination of the morphology of an example of the type species of each genus, or a substitute species if the true identity of the type species is in doubt. The mouthparts are described for each type species, often for the first time, providing additional characters for phylogenetic analysis. Genera are diagnosed using the taxonomic database program DELTA (Dalwitz et al. 1999). This database is also used for a phylogenetic analysis of the genera using PAUP (Swofford 2000). Proposed taxonomic changes resulting from this study are summarised as follows. The family Pronoidae is restricted to the monotypic genus Pronoe because it has some unique characters not found in any other platysceloidean. Paralycaea, previously in Pronoidae, has characters in common with Amphithyrus and Amphithyropsis gen. nov., a new genus proposed for Paralycaea platycephala Zeidler, 1998 (here re-determined a junior synonym of Tetrathyrus pulchellus Barnard, 1930), and together they form the proposed new family Amphithyridae fam. nov. Eupronoe and Parapronoe, also previously in Pronoidae, are similar in the morphology of the mouthparts, antennae and gnathopoda, and together form the proposed new family Eupronoidae fam. nov. The family Brachyscelidae is restricted to the genus Brachyscelus because Thamneus, previously included in Brachyscelidae, has a number of characters that differ considerably from any other genus of Hyperiidea and it is therefore placed in a family of its own, Thamneidae fam. nov. The status of the family Anapronoidae, for Anapronoe, is confirmed, as is the status of the family Tryphanidae for Tryphana. The family Lycaeidae is limited to Lycaea and Simorhynchotus. The family Oxycephalidae maybe polyphyletic but more work is required to resolve the systematic status of the eight genera currently recognised. Metalycaea globosa Stephensen, 1925, sometimes included in the Oxycephalidae, is confirmed to be a junior synonym of Lycaea serrata Claus, 1879. The family Platyscelidae is restricted to four genera, Platyscelus, Paratyphis, Hemityphis and Tetrathyrus; Amphithyrus having been removed to the new family Amphithyridae. The family Parascelidae is also restricted to four genera, Parascelus, Thyropus, Schizoscelus and Euscelus. Hemiscelus, previously included in this family, is regarded a junior synonym of Hemityphis. Keys are provided for families, genera and all currently known species. All records of associations with gelatinous zooplankton are also documented, providing additional data to help resolve the phylogeny and evolutionary origins of the Hyperiidae.

A new Glossocephalus (Crustacea: Amphipoda: Hyperiidea: Oxycephalidae) from deep-water in the Monterey Bay region, California, USA, with an overview of the genus

A new species of Glossocephalus, G. rebecae sp. nov., is described from deep-water in the Monterey Bay region of California, Eastern Pacific Ocean. It seems to be associated exclusively with the mesopelagic ctenophore Bathocyroe fosteri. This association has been observed from 541-830 m depth. It is readily distinguished from G. milneedwardsi Bovallius, 1887 by the shape of the eye fields. The retina is organised into a crescent-shaped organ, occupying about one-quarter of the back half of the head, with the crystalline cones projecting both anteriorly and laterally. An updated review of the genus is provided, taking into account the new species, together with an overview of G. milneedwardsi, and three new records of associations with ctenophores for G. milneedwardsi. New observations on the interaction of G. milneedwardsi with one of its ctenophore hosts, Mnemiopsis sp., are also documented.

New information and locality records for the Antarctic amphipod Clarencia Chelata K. H. Barnard, 1931, and a reappraisal of the family Clarenciidae J. L. Barnard & Karaman, 1987 (amphipoda, Gammaridea)

An examination of fresh material of Clarencia chelata K. H. Barnard, 1931, collected from the Prydz Bay region, Antarctica, has revealed a number of characters not recognised previously or diagnosed incorrectly. New morphological information is provided and the systematic position of Clarenciidae is re-evaluated and a new superfamily Clarencioidea is proposed. A new diagnosis for Clarenciidae is also provided. The species seems to be associated with the white sponge Asbestopluma belgicae (Topsent, 1901) (Cladorhizidae).