On the taxonomic status of the genus <i>Parathyone</i> (Echinodermata, Holothurioidea, Dendrochirotida)

The genus Parathyone Deichmann, 1957 encloses two species, Parathyone surinamensis and Parathyone suspecta, and is close to the genus Ocnus Forbes, 1841. Ekmanothyone nomen novum is erected to replace the pre-occupied Parathyone Cherbonnier, 1988 (non Parathyone Deichmann, 1957)

Ossicle variation in Antarctic dendrochirote holothurians (Echinodermata)

A study of ossicle variation in Cucumariidae coming from the Weddell Sea (antarctica), the specimens ranging from 4 to 70 mm long, confirms that Heterocucumis steineni (Ludwig, 1898), Heterocucumis antarctica (Vaney, 1906) and Heterocucumis godfroyi (Vaney, 1914) represent different stages of a single species: H. steineni. A study of Heterocucumis steineni, H. denticulata (Ekman, 1927) and Staurocucumis liouvillei (Vaney, 1914) shows that the main ossicle change occurs early when specimens are 20 mm long or even less. A review of holothurian ossicle variation is given

The Holothurioidea (Echinodermata) collected during the Tyro Mauritania-II expedition 1988

During the Tyro Mauritania-II expedition (5-21.vi.1988) 15 holothurian species were collected between 19 and 1,900 m depth. Twelve species are new to the fauna of Mauritania, including Paracucumaria deridderae spec. nov. Mauritania represents the southern distribution limit of four species also known from Europe, and the northern distribution limit of five species also known from southern Africa

The holothurians of Easter Island

The holothurians collected during the "DIS RAPA NUI 270" Expedition (27-11-93 to 24-12-93) at Easter Island are described together with all the species already mentioned from the Island. Nine species are known. Distribution, variability and endemism of these species are discussed

Biologie et écologie de <i>Leptoconchus peronii</i> (Lamarck, 1818) (Gastropoda, Coralliophilidae) récolté en Papouasie Nouvelle-Guinée, avec une redescription de l'espèce

Leptoconchus peronii lives in faviid corals and nearly always between 3 and 7m depth. Female shell shape varies with the coral host. Most of the L. peronii are living in pairs, the male being smaller than the female, sometimes dwarfish. The female broods about ten egg capsules in the mantle cavity. The microsculpture of the larval shell is not a specific character. The siphon is partly and longitudinally divided over all its lenght. The type series of Leptoconchus peronii (Lamarck, 1818) is described and figured for the first time. Leptoconchus striatus Rüppel, 1835, type species of the genus Leptoconchus, and Leptoconchus schrenkii Lischke, 1871 are to be considered as synonyms of L. peronii

<i>Reliquiaecava</i>, a new genus of Coralliophilidae (Mollusca, Gastropoda)

A new genus Reliquiaecava gen. n. is proposed for the species Leptoconchus robillardi Liénard, 1870. This new genus is created because the adult and embryonic shells and the ecology of the adult of the above mentioned species are very different from those of species belonging to the genera Leptoconchus, Coralliophila, and Coralliobia genera to which the species was formerly assigned in the literature. Probably, the two varieties described in the original description by Liénard, represent two different species

Holothuries (Echinodermata) récoltées sur le talus continental méditerranéen (NW) lors de la campagne DEPRO96 = Holothurians (Echinodermata) collected on the Mediterranean continental slope during the DEPRO96 cruise

Six holothurian species have been collected during the DEPR096 cruise. Ypsilothuria bitentaculata attenuata is new for the French fauna and is mentioned for the second time from the Mediterranean Sea. Ocnus planci and Trachythyone tergestina, previously known only from the continental shelf, are now mentioned from the continental slope

Contribution to the knowledge of two boring gastropods with an annotated list of the genera <i>Magilus</i> Monfort, 1810 and <i>Leptoconchus</i> Ruppell, 1835

Magilus antiquus MONTFORT , 1810 is an active borer, digging a hole in front of its tube. This hole communicates with the exterior by a short chimney. The small operculum of Magilus spp. is unable to close the aperture of the tube but does close the chimney well. The tube orientation could not be related to any constancy. Leptoconchus striatus RÜPPELL, 1835 has a post-larval free-living stage. The young shell sinks down actively in the coral host. Communicating burrows of L. striatus could be the result of young animals developing around their mother shell. Diagnosis are proposed for the genera Magilus MONTFORT, 1810 and Leptoconchus RÜPPELL, 1835. Magilus sowerbyi nomen novum is proposed in place of M. costatus SOWERBY in REEVE, 1872. The genus Magilus includes six recent species: M. antiquus, M. cumingii, M. japonicus, M. lankae, M. m.icrocephalus, and M. sowerbyi. M. japonicus and M. lankae could be subspecies of M. antiquus. « Magilus serpuliformis VONLAIN » in DERANIY AGALA (1968) must be related to the Leptoconchus includes fourteen recent species: L. cumingii, L. cuvieri, L. djedah, L. ellipticus, L. expolitus, L. globulosus, L. lamarckii, L. maillardi, L. noumeae, L. rostratus, L. rueppellii, L. serratus, L. solidiusculus, and L. striatus. L. peronii is a nomen oblitum and L. oblongus a nomen nudum. L. schrenckii and L. tenuis are to be considered synonyms of L. striatus. Under the names L. ellipticus, L. expolitus, and L. rostratus, maybe there are in each case two different species. Coralliobia fimbriata, C. robillardi, and C. smithi, which have been assigned to the genera Magilus and/or Leptoconchus, must be reported to the genus Coralliobia

Note sur deux holothuries nouvelles pour la faune belge

Aslia lefevrei (Barrois, 1882) and Neopentadactyla mixta (Oestergren, 1898) are mentioned for the first time along the Belgian coast. Both species are described and their spicules figured. Their distribution is shortly discussed