Orostylis gen. nov., a new genus of Dalytyphloplanida with seven new species (Platyhelminthes: Rhabdocoela).

We describe a new genus of dalytyphloplanid rhabdocoels, with seven new species. Orostylis gen. nov. has a unique combination of characters including the presence of a sclerotised stylet, an anteriorly positioned male copulatory organ with the male genital pore in the buccal cavity, and the absence of an oviduct. The ovary empties directly into the intestinal lumen. Orostylis dohae sp. nov., Orostylis asinaraensis sp. nov., Orostylis caecus sp. nov., Orostylis distortus sp. nov., Orostylis donanae sp. nov., Orostylis gallicus sp. nov., and Orostylis timucuorum sp. nov. are distinguished from each other by the structure of the sclerotised parts of the male copulatory organ. Molecular and morphological evidence place the new genus in Neodalyellida Willems et al. 2006, and similarities with other taxa are discussed.

A revision of the genus Cheliplana de Beauchamp, 1927 (Rhabdocoela: Schizorhynchia), with the description of six new species.

A comprehensive morphological and taxonomic account of the members of the genus Cheliplana de Beauchamp, 1927 is presented. Six new species are described: Cheliplana asinaraensis n. sp., C. cubana n. sp., C. curacaoensis n. sp., C. hawaiiensis n. sp., C. longissima n. sp. and C. mauii n. sp. The new species are mainly distinguished from each other and from other representatives of Cheliplana by the organisation of the reproductive system and the structure of the cirrus. Furthermore, C. triductibus Van Steenkiste, Volonterio, Schockaert Artois, 2008 is considered a junior synonym of Cheliplana deverticula Ax, 2008. The two subspecies of Cheliplana asica Marcus, 1952, C. asica asica and C. asica terminalis Brunet, 1968, are considered separate species. The systematic position of the genus Dactyloplana Armonies, 2018 is discussed, and its synonymy with Cheliplana is retained. As such, this brings the total number of species of Cheliplana to 49. Finally, we provide an identification key to the members of the genus, based on characters that enable identification to species level in the field.

Taxonomy and phylogeny of Koinocystididae (Platyhelminthes, Kalyptorhynchia), with the description of three new genera and twelve new species.

The taxon Koinocystididae is the third most species-rich family within Eukalyptorhynchia. However, its diversity and phylogeny have been largely neglected in former studies. We introduce three new genera and twelve new species of Koinocystididae including Simplexcystis asymmetrica gen. n. sp. n., Galapagetula cubensis sp. n., eight species of Reinhardorhynchus gen. n. and two species of Itaipusa. This raises the total number of species within Koinocystididae from 51 to 63. We also report on new distribution records for six known species: I. divae (Cuba, Panama and New Caledonia), I. karlingi (Sardinia and Lanzarote), Reinhardorhynchus riegeri comb. n. (Cuba), R. ruffinjonesi comb. n. (Cuba and Panama), Utelga heinckei (Cuba and Lanzarote), and U. pseudoheinckei (Sardinia). Simplexcystis asymmetrica gen. n. sp. n. is characterised by a male duct running eccentrically through the copulatory bulb, lack of any hard structures in the male system, lack of a bursa, and the fact that the epithelia of the female, the male, and part of the common atrium are covered by a brush border. Galapagetula cubensis sp. n. has a caudal gonopore, a divisa-type copulatory bulb with an unarmed penis papilla, and a female duct without a sphincter. The new species of Itaipusa and Reinhardorhynchus gen. n. differ from their congeners in the detailed structure of the copulatory bulb and especially the hard structures associated with it. In a molecular phylogenetic analysis based on all available 18S and 28S rDNA sequences of koinocystidids, we found support for the monophyly of the family and the genus Utelga Marcus, 1949. The genus Itaipusa is not monophyletic in that I. sinensis forms a clade with Rhinolasius dillonicus, while other species of Itaipusa that have a copulatory bulb armed with hooks form a clade together with Sekerana stolzi. As the type species of Itaipusa (I. divae) is in neither of these clades, we erected a new genus for I. sinensis (Koinogladius gen. n.) and one for species of Itaipusa having a hook-bearing copulatory bulb (Reinhardorhynchus gen. n.), respectively. Whether the remaining species of Itaipusa form a monophylum remains uncertain.

Schizorhynchia (Platyhelminthes, Rhabdocoela) from eastern Cuba, with the description of fifteen new species.

We report on the schizorhynch species collected in a survey in the eastern region of Cuba. Eighteen species were identified, of which only three are known to science: Cheliplana asica, C. terminalis, and Carcharodorhynchus flavidus. The 15 new species belong to three different genera: Cheliplana (five species), Carcharodorhynchus (four species), and Schizochilus (six species). The five new species of Cheliplana (C. gibarenha sp. n., C. santiaguera sp. n., C. spuriaseminalis sp. n., C. subproximalis sp. n. and C. verrucosa sp. n.) differ from their congeners in the detailed morphology of the proboscis hooks and the atrial organs. The proboscis hooks bear a distal small hook in C. verrucosa sp. n., a feature only shared with C. paradoxa. Two of the four new species of Carcharodorhynchus (C. smilodon sp. n. and C. papillaris sp. n. ) are very similar to C. flavidus in that the toothed belts of the proboscis are not continuous. However, they clearly differ from that species and from each other in the detailed construction of the teeth and copulatory organ. Carcharodorhynchus spiniformis sp. n. and C. nativus sp. n. can also be distinguished from the other species of Carcharodorhynchus by the detailed construction of the proboscis teeth and copulatory organ. The six new species of Schizochilus here described show a spiny cirrus around a central stylet. Two species lack the distal sclerotized cap of the copulatory bulb: S. favus sp. n. and S. bueycabonensis sp. n.. All new species of Schizochilus can be distinguished from each other and their congeners by the detailed construction of the hard parts (cirrus and stylet) of the copulatory organ.

On the genus Typhlopolycystis Karling, 1956 (Platyhelminthes, Kalyptorhynchia, Polycystididae), with data on the five known species and the description of eleven new species.

An overview is given of all representatives of the genus Typhlopolycystis Karling, 1956: the five known species (T. coeca Karling, 1956; T. mediterranea Brunet, 1965; T. coomansi Schockaert and Karling, 1975; T. schockaerti Karling, 1978 and T. rubra Noldt and Reise, 1985) and eleven new species: T. microphthalma n. sp. from S. France, T. fonsecai n. sp. and T. maikoni n. sp. from Brazil, T. norenburgi n. sp. and T. leasiae n.sp from the Pacific coast of Panama, T. pluvialiae n. sp. from Lanzarote (Canary Islands, Spain), T. riegeri n. sp. from Tanzania, T. tahitienis n. sp. from French Polynesia, T. australiensis n. sp. from South Australia, T. sarda n. sp. from Sardinia (Italy), the S. of France and from Lanzarote, and T. errata n. sp. from Sardinia (Italy). We consider T. limicola Schilke, 1970 as a species inquirenda of which no type material exists. Finally, some comments are given on the distribution of the genus of which representatives have been found in almost all places that have been sampled world wide.

Four new species of the genus Paraustrorhynchus (Rhabdocoela: Kalyptorhynchia: Polycystididae).

Four new species of Paraustrorhynchus (Rhabdocoela: Kalyptorhynchia: Polycystididae) are described: two from Southern China (P. shenda n. sp., P. sinensis n. sp.), one from New Caledonia (P. isoldeae n. sp.), and one from India (P. smeetsae n. sp.). All four species show a typical dark blue dorsal pigmentation pattern, which is unique to the genus. This pigment forms a broad longitudinal line in P. shenda n. sp. and P. sinensis n. sp., shows an additional transverse band at the level of the pharynx in P. smeetsae n. sp. and forms a Y-shaped pattern in P. isoldeae n. sp. The four species can also be distinguished from each other and their congeners by the detailed morphology of the hard parts of the male system, which in all cases consists of an L-shaped (P. shenda n. sp., P. isoldeae n. sp) or slightly-curved (P. smeetsae n. sp., P. sinensis n. sp.) prostate stylet type II and a prostate stylet type III, which consists of three plates: a basal plate from which two longer plates depart, each with a distal serrated rim. A phylogenetic analysis based on 18S and 28S-rDNA data indicates that Paraustrorhynchus is a monophyletic taxon within Polycystidinae, with Alcha evelinae as the sister group.

First record of Polycystididae (Platyhelminthes, Kalyptorhynchia) from Cuba, with the description of a new genus and five new species, and remarks and the description of one new species from Panama.

The first records of Polycystididae from Cuba are provided and discussed. In total nine species have been collected, five of which are new to science, one representing a new genus. Polycydora intermedia gen. n. sp. n. shows intermediate features between Polycystis Kölliker, 1845 and Paulodora Marcus, 1948. The ovaries are kidney shaped, with the oocytes arranged in a row, and lack the hard "nozzles" of Paulodora. A female bursa as in Polycystis is present. In P. intermedia gen. n. sp. n. lacks the strong muscle bulb at the male bursa and the accessory glands type I in the male atrium, which are present in Polycystis. The male atrial organs include a prostate stylet type II connected to a free prostate vesicle type II. The four new species (Phonorhynchoides minor sp. n., Phonorhynchopsis capillaris sp. n., Phonorhynchopsis sublinguatus sp. n., Myobulla armenterosi sp. n.) are distinguished from their congeners by the specific shape and length of the male hard copulatory structures. Phonorhynchoides minor sp. n. has the smallest stylets within the genus, and these stylets are more straight than those of the other species of the genus. In Phonorhynchopsis capillaris sp. n. the prostate stylet type IV is only 20% of the length of the accessory stylet type IV, the lowest relative length within the genus. The accessory stylet in this species is extremely thin; it is only 2 µm wide. Phonorhynchopsis sublinguatus sp. n. has a prostate stylet widened in the distal half, ending in a rounded tip, not twisted in the middle. Because of its strong resemblance to M. armenterosi sp. n., M. berti sp. n., a new species of Myobulla Artois Schockaert, 2000 collected at the Atlantic coast of Panama is described here too. Both species of Myobulla have a prostate stylet type III that shows a 90° turn at some point, as is the case in some other species of Myobulla. In M. berti sp. n. the stylet is smaller overall and is bent in the middle; in M. armenterosi sp. n. the stylet is larger and it is bent more distally. All of the four known species have a very wide geographical distribution: Phonorhynchopsis haegheni, Alcha evelinae, Paraustrorhynchus elixus, and Gyratrix hermaphroditus.

Kalyptorhynchia (Platyhelminthes: Rhabdocoela) from KwaZulu-Natal (South Africa), with the description of six new species.

Fifteen species of kalyptorhynch flatworms, twelve of them eukalyptorhynchs and three schizorhynchs, are reported from the KwaZulu-Natal coast in South Africa. Six species are new to science, five of which belong to Eukalyptorhynchia, the remaining one to Schizorhynchia. One of the new eukalyptorhynch species, Uncinorhynchus linusi n. sp., belongs to the taxon Gnathorhynchidae Meixner, 1929 and can be distinguished from other species of Uncinorhynchus Karling, 1947 based on the detailed structure of the proboscis hooks and the hard part in the male genital system. Two other species are members of the Koinocystididae Meixner, 1924. Itaipusa sbui n. sp. is characterised by an armed cirrus with two transversal bands of lamellar spines and by the detailed structure of the female genital system. The other new koinocystidid cannot be placed in any existing taxon and therefore a new genus is erected: Bhambathorhynchus abursalis n. gen. n. sp. It is characterised by the presence of two bent hooks in the male system, each one connected to a muscular bulb, and by the absence of a copulatory bursa. The remaining two new species of Eukalyptorhynchia, Lagenopolycystis mandelai n. sp. and Phonorhynchoides gondwanae n. sp., are members of the taxon Polycystididae Graff, 1905 and can be distinguished from their respective congeners by the detailed structure of their hard parts in the male genital system. The latter species also occurs on the Indian subcontinent. The discussion on the phylogenetic position of the new species of Phonorhynchoides leads to the formal split of this non-monophyletic genus into two taxa: Phonorhynchoides Beklemischev, 1927 and Phonorhynchopsis n. gen. The sixth and last new species, Baltoplana cupressus n. sp., is a member of the taxon Cheliplanidae Schilke, 1970 (Schizorhynchia) and combines an armed cirrus with a single accessory cirrus in the copulatory organ. For two more species, Prognathorhynchus spec. and Carcharodorhynchus spec., the available material is inadequate for a formal description, but they are mentioned and illustrated to allow future recognition. Six known species, Pocillorhynchus spiroductus Schockaert, 1982, Duplacrorhynchus heyleni Artois & Schockaert, 1999, Gyratrix hermaphroditus Ehrenberg, 1831, Paulodora contortoides Artois & Tessens, 2008, P. drepanophora Artois & Tessens, 2008 and Cheliplana pileola Jouk & De Vocht, 1989 are reported from South Africa for the first time and additional remarks on their morphology are given. An additional species, Brachyrhynchoides oosterlyncki (Willems, Reygel & Artois, 2013) Willems, Reygel & Artois, 2013 was recently described from South Africa and India (see Artois et al., 2013b, 2013c), and is mentioned here for the sake of completeness.

Brachyrhynchus n. gen. n. sp., a new genus of Polycystididae Graff, 1905 (Rhabdocoela: Kalyptorhynchia), with the description of three new species from the Mediterranean and the Indian Ocean.

Three new species of Polycystididae are described: Brachyrhynchus triplostylis n. gen. n. sp., B. acutus n. sp. and B. oosterlyncki n. sp. They are the first species of Polycystididae to be described with a second, single-walled accessory stylet connected to a small glandular vesicle in the male system. The three species can be distinguished from each other by the detailed morphology and the relative lengths of the three stylets in the male system. The relationships of these species with other representatives of Polycystididae are discussed.