Article 23.9 of the Code, introduced in its last 1999 version, allows the validation, in some cases, of a well known junior synonym or homonym as opposed to a senior synonym or homonym that had been ignored in the literature after 1899. In such cases, the junior nomen qualifies as a nomen protectum and the senior one as a nomen oblitum, a formula redefined in a new sense in this edition. The implementation of this Article requires one to follow strictly several conditions: the invalidation can concern only senior synonyms or homonyms (a junior one cannot be a nomen oblitum); it must have been published in the sense given to this term in the Code (i.e., it cannot have been proposed online in an unpublished electronic document); and evidence must be published that the junior synonym or homonym has been used as valid for the same taxon in at least 25 works published by at least 10 authors in the immediately preceding 50 years and encompassing a span of not less than 10 years. A nomen oblitum remains an available nomen and can be revalidated subsequently, for example in the case of re-evaluation of a subjective synonymy. Since the implementation of this new Article, some authors have used it without respecting these conditions or some of them: in such cases, the nomenclatural act supposed to have been effected under Article 23.9 is null and void, and the regular Rules of the Code must be applied (e.g., through validation of the senior synonym or homonym). A few examples concerning amphibian nomina of the family Hylidae illustrate these statements. The statuses of the nomina, spellings, emendations and combinations Hyla fulva, Hyla gaimardi, Hyla lesueurii,Hyla lesueuri, Hyla prasina, Hyla quoyi, Hyla septentrionalis, Hyla suerii, Hyla sueurii, Rana gaimardii,Istriurus lesueurii, Istriurus sueurii and Trachycephalus marmoratus are discussed. A lectophoront (lectotype) is designated for Hyla septentrionalis and Trachycephalus marmoratus and neophoronts (neotypes) are designated for Hyla fulva, Hyla gaimardi and Hyla sueurii.

Rare species of three long-lived lucinid genera, GibbolucinaCossmann, 1904, BarbierellaChavan, 1938 and Retrolucina n. gen., with origins in the Paleocene and Eocene of western Tethys, are present in the Mozambique Channel area of the southwestern Indian Ocean but absent elsewhere in the Indo-West Pacific. A new species, Gibbolucina zelee n. sp., is described from the Banc de la Zélée and western Madagascar that resembles Miocene species from western France. Since their origin in the Paleocene to the present day Barbierella species have always been rare. New records and images, including syntypes, are provided for Barbierella louisensis (Viader, 1951) from Mauritius and the Mozambique Channel, with Barbierella scitulaOliver & Abou-Zeid, 1986 from the Red Sea regarded as synonym. A new genus, Retrolucina n. gen., is proposed with the living Lucina voorhoeveiDeshayes, 1857 (usually called Eomiltha voorhoevei) as type species and also including Lucina defranceiDeshayes, 1857, a strikingly similar species from the Eocene of the Paris Basin. Retrolucina n. gen. differs from EomilthaCossmann, 1912 in shape, sculpture and hinge characters. MonitiloraIredale, 1930, another genus of Paleocene or earlier origins, includes a few living species in the Indo-West Pacific and is now identified from Mozambique with Monitilora sepes (Barnard, 1964) (formerly Phacoides sepesBarnard, 1964). It is suggested that Gibbolucina, Barbierella and Retrolucina n. gen. species became isolated in the western Indian Ocean following the closure of the Tethyan Seaway in the early Miocene while their congeners in western Tethys became extinct. The survival of these rare genera, with restricted geographical ranges and seemingly small populations, runs counter to current ideas concerning long-term extinction risk.

Le complexe Cicadetta montana (Scopoli, 1772) sensu lato comprend six espèces en France, Corse incluse. Des prospections menées fin juin 2016 dans la région de Tende (Alpes-Maritimes) ont permis d'avérer la présence dans ce complexe d'une septième espèce : C. sibillae Hertach & Trilar, 2015, cigale récemment décrite d'Italie et de Suisse (Hertach et al. 2015). Son écologie est abordée et une première carte de répartition est dressée. Très proche morphologiquement de C. cerdaniensisPuissant & Boulard, 2000, l'examen des genitalia de C. sibillae fait apparaître des caractères morphologiques nouveaux, notamment dans la forme des pseudoparamères. En outre, la base des ailes antérieures des populations de C. sibillae de France a tendance à être plus claire que chez les spécimens d'Italie et de Suisse. Cependant, l'étude des paramètres acoustiques spécifiques définis par Hertach et al. (2015) ne révèle pas de différences significatives pour les mâles enregistrés en France, leurs émissions sonores étant très proches de celles émises par les mâles des populations ouest alpines d'Italie. Des analyses fréquentielles poussées font apparaître un fonctionnement inattendu des cymbales qui produisent des sons complexes par leurs gammes de fréquences différenciées, chacune de ces gammes étant associée au fonctionnement de chaque cymbale. Ce fonctionnement complexe est pour la première fois avéré en milieu naturel, n'ayant été exploré jusqu'alors que chez une autre espèce, Tympanistalna gastrica (Stål, 1854), en laboratoire dans des conditions expérimentales contrôlées. Une clef d'identification acoustique inédite des sept taxons du genre Cicadetta Kolenati, 1857 présents en France est proposée.

Squalus rancureli Fourmanoir, 1979 and S. melanurusFourmanoir, 1979 are deep-sea sharks described from off New Caledonia and Vanuatu. Morphological separation between them is limited to caudal fin coloration and a few morphometric characters. These two nominal species were described as new in more than one taxonomic account, thus requiring nomenclatural elucidation. Taxonomic complexity behind S. rancureli and S. melanurus has been disregarded and underestimated in previous studies, and indicated to rely on propagation of erroneous authorship and negligence of requirements from the International Code on Zoological Nomenclature for describing new taxa. Analysis of type material and topotypic specimens revealed congruency of external morphology, external measurements and meristic data, suggesting conspecificity. Squalus rancureli is herein considered a junior synonym of S. melanurus, and authorship of these nominal species is clarified. Differential diagnosis and redescription of S. melanurus and an updated diagnosis of S. bucephalus Last, Séret & Pogonoski, 2007 are also provided based on new material. Comparative examinations with other regional congeners support their validity and recognition of a third species provisionally identified as Squalus cf. montalbani. Squalus melanurus is easily distinguished from S. bucephalus Last, Séret & Pogonoski, 2007 by bearing a black caudal-fin lower lobe, snout conspicuously elongate, dermal denticles tricuspidate, and smaller number of vertebrae (vs whitish caudal-fin lower lobe, snout conspicuously short, dermal denticles unicuspidate, higher number of vertebrae).

The Paronellini Börner, 1906 of Africa and Madagascar are poorly known. Nineteen Paronella-like species have been reported from Africa, but it is unclear how they are distributed among genera as currently defined. Here we review all references containing descriptions and reports of Paronella-like species from Africa, Madagascar and the Seychelles. And based on that information we propose generic allocations for all forms. As a result, 11 species are referred to TrogolaphysaMills, 1938; three to ParonellaSchött, 1893; one to Troglopedetes Absolon, 1907; one may be assigned to either Trogolaphysa or Lepidonella Yosii, 1960; one could be placed in TrichoryphaSchött, 1893 or Paronella, and two are nomina nuda. For all forms referred to as Trogolaphysa we provide a short list of synonymy, diagnosis, and an identification key. We also described a new species, Trogolaphysa judithnajtae n. sp., from Madagascar, which is distinguished from Trogolaphysa wahlgreni (Mitra, 2002) n. comb. by being blue instead of white, lacking labral papillae, and having two rows of spines on the dens instead of one.

Seven new species of subterranean and endogean terrestrial isopods from Tuscany (central Italy) are described in the families Trichoniscidae Sars, 1899 (Leucocyphoniscus pisanus n. sp., Moserius gruberae n. sp., Moserius talamonensis n. sp.) and Armadillidiidae Brandt, 1833 (Typhlarmadillidium occidentale n. sp., Paraschizidium ferrarai n. sp., Trogleluma pilosa n. sp. and Alloschizidium labronicum n. sp.). The diagnostic characters and the affinities of the new species are discussed.