European Journal of Taxonomy <p>The <em>European Journal of Taxonomy</em> is a peer-reviewed international journal in descriptive taxonomy, covering the eukaryotic world. Its content is fully electronic and <a href="">Open Access</a>. It is published and funded by a <a href="">consortium</a> of European natural history institutions. Neither authors nor readers have to pay fees. All articles published in <em>EJT</em> are compliant with the different nomenclatural codes. <em>EJT</em> is an archived and indexed journal that welcomes scientific contributions from all over the world, both in content and authorship. If you have any questions about <em>EJT</em>, please <a href="">contact us</a></p> EJT Consortium en-US European Journal of Taxonomy 2118-9773 <h3>Creative Commons Copyright Notices</h3> <div class="page"> <p>Authors who publish with this journal agree to the following terms:</p> <ol> <li class="show">Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a&nbsp;<a href="">Creative Commons Attribution License</a> (CC BY 4.0) that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.</li> <li class="show">Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.</li> <li class="show">Authors are NOT ALLOWED TO post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to taxonomic issues.</li> </ol> </div> New fossil genus and new extant species of diatoms (Stephanodiscaceae, Bacillariophyceae) from Pleistocene sediments in the Neotropics (Guatemala, Central America): adaptation to a changing environment? <p>Several taxa of Stephanodiscaceae were found in the upper section of Pleistocene sediments from Lake Petén-Itzá (Guatemala). A new fossil genus <em>Cyclocostis</em> Paillès gen.&nbsp;nov. and new extant species <em>Discostella gabinii</em> Paillès &amp; Sylvestre sp. nov. are described. <em>Cyclocostis</em> gen.&nbsp;nov. is characterized by a strongly tangentially undulated valve surface, coarse unequal striation reaching a central punctum in the valve center, an absence of central lamina and domed criba, widely open alveoli with one median recessed costa bearing marginal fultoportulae and a single rimoportula all within a ring. A single valve face fultoportula is present on the raised part of the valve opposite the rimoportula. Differences relative to similar genera and the delimitation of a new genus are discussed. <em>Discostella gabinii</em> sp.&nbsp;nov. is distinguished by circular and flat valves, a small central area bearing 5 to &gt; 30 scattered large areolae giving a colliculate appearance, medium-sized alveoli, marginal fultoportulae on every 4–5th costa, a single rimoportula and internally smooth valve center. Differences to similar taxa in the genus <em>Discostella</em> are discussed. The succession of the species of <em>Cyclotella</em>, <em>Discostella</em> and <em>Cyclocostis</em> gen.&nbsp;nov. in our record could represent eco-phenotypic responses to particular environmental stress / change.</p> Christine Paillès Florence Sylvestre Alain Tonetto Jean-Charles Mazur Sandrine Conrod Copyright (c) 2020 Christine Paillès, Florence Sylvestre, Alain Tonetto, Jean-Charles Mazur, Sandrine Conrod 2020-11-30 2020-11-30 726 1 23 10.5852/ejt.2020.726.1169 The ‘red-tailed’ Lasioglossum (Dialictus) (Hymenoptera: Halictidae) of the western Nearctic <p>Sweat bees in the subgenus <em>Lasioglossum</em> (<em>Dialictus</em>) are one of the most diverse and abundant bee taxa, and a critically important component of bee biodiversity. Yet, the most basic taxonomic knowledge of these bees is lacking in many regions. As a step towards a better understanding of the <em>L.</em> (<em>Dialictus</em>) of the western Nearctic region, a revision of the ‘red-tailed’ <em>L.</em> (<em>Dialictus</em>) species was completed. Thirty-six species were revised, 20 of which are described as new, and two names are treated as junior subjective synonyms. Descriptions, figures, distribution maps, floral hosts, and keys to species for females and males are provided. The following 20 species are described as new: <em>Lasioglossum</em> (<em>Dialictus</em>) <em>arenisaltans</em> sp. nov., <em>L.</em> (<em>D.</em>) <em>argammon</em> sp. nov., <em>L.</em> (<em>D.</em>) <em> austerum</em> sp. nov., <em>L.</em> (<em>D.</em>) <em>cactorum</em> sp. nov., <em>L.</em> (<em>D.</em>) <em>cembrilacus</em> sp. nov., <em>L.</em> (<em>D.</em>) <em>clastipedion</em> sp. nov., <em>L.</em> (<em>D.</em>) <em>clavicorne</em> sp. nov., <em>L.</em> (<em>D.</em>) <em>decorum</em> sp. nov., <em>L.</em> (<em>D.</em>) <em>festinum</em> sp. nov., <em>L.</em> (<em>D.</em>) <em>imbriumbrae</em> sp. nov., <em>L.</em> (<em>D.</em>) <em>julipile</em> sp. nov., <em>L.</em> (<em>D.</em>) <em>lilianae</em> sp. nov., <em>L.</em> (<em>D.</em>) <em>meteorum</em> sp. nov., <em>L.</em> (<em>D.</em>) <em>miltolepoides</em> sp. nov., <em>L.</em> (<em>D.</em>) <em>minckleyi</em> sp. nov., <em>L.</em> (<em>D.</em>) <em>perditum</em> sp. nov., <em>L.</em> (<em>D.</em>) <em>rufornatum</em> sp. nov., <em>L.</em> (<em>D. </em>) <em>spivakae</em> sp. nov., <em>L.</em> (<em>D.</em>) <em> tessellatosum</em> sp. nov., and <em>L.</em> (<em>D.</em>) <em>torrens</em> sp. nov. Previously unknown males of <em>L.</em> (<em>D.</em>) <em>clematisellum</em> (Cockerell, 1904), <em>L.</em> (<em>D.</em>) <em>droegei</em> Gibbs, 2009, <em>L.</em> (<em>D.</em>) <em>kunzei</em> (Cockerell, 1898), and L. (<em>D.</em>) <em>pallidellum</em> (Ellis, 1914) are described and figured for the first time. <em>Lasioglossum</em> (<em>Dialictus</em>) <em>clarissimum</em> (Ellis, 1914) (= <em>Halictus clarissimus</em> Ellis, 1914) and <em>L.</em> (<em>D.</em>) <em>perexiguum</em> (Sandhouse, 1924) (= <em>Halictus</em> (<em>Chloralictus</em>) <em>perexiguus</em> Sandhouse, 1924) are new subjective junior synonyms of <em>L. mesillense</em> (Cockerell, 1898) (= <em>Halictus nymphalis</em> var. <em>mesillensis</em> Cockerell, 1898). A lectotype specimen is newly designated for <em>L. mesillense</em>, for which the location of the type material has not previously been known. The following five new records for Mexico are reported: <em>L. clematisellum</em>, <em>L. droegei</em>, <em>L. eophilus</em> (Ellis, 1914), <em>L. kunzei</em>, and <em>L. pallidellum</em>.</p> Joel Gardner Jason Gibbs Copyright (c) 2020 Joel Gardner, Jason Gibbs 2020-11-27 2020-11-27 726 1 242 10.5852/ejt.2020.725.1167 A new species and depth record of bopyrid (Crustacea, Isopoda) from a squat lobster in the Kuril-Kamchatka Trench <p>The branchial parasitic isopod <em>Pleurocryptella altalis</em> sp. nov. (Bopyridae: Pseudioninae) is described from the squat lobster host <em>Munidopsis petalorhyncha</em> Baba, 2005. The new species is morphologically similar to <em>Pleurocryptella formosa</em> Bonnier, 1900 and <em>P. wolffi</em> Bourdon, 1972b but can be distinguished based on male characters (differences in head, pleon and uropods) and female characters (differences in barbula, pleopods and pleotelson). The parasite specimens (a female and male pair) were collected with the squat lobster host at a depth of 5060–5130 m from the Kuril-Kamchatka Trench, representing the deepest record for any of the 850+ described bopyrid isopod species and for any record of an infested host. Dichotomous identification keys to females and males of <em>Pleurocryptella</em> species and subspecies are provided.</p> Jason D. Williams Christopher B. Boyko Ivan N. Marin Copyright (c) 2020 Jason D. Williams, Christopher B. Boyko, Ivan N. Marin 2020-11-26 2020-11-26 726 122 133 10.5852/ejt.2020.724.1165 A new Dicranophragma (Diptera: Limoniidae) from a hypogeous environment in Catalonia (Iberian Peninsula) <p>A new species of Limnophilinae (Diptera: Limoniidae), <em>Dicranophragma (Brachylimnophila) relictum</em> Mederos sp.&nbsp;nov., is described. This is the third species of this genus recorded from the Iberian Peninsula. This new species was discovered in a cave in the Sant Llorenç del Munt i Serra de l’Obac Natural Park, Barcelona Province (Catalonia) and it is the first record of a species of this genus from a hypogeous environment. The absence of suitable ecological conditions for the survival of this new species, particularly in the vicinity of the cave, suggests that this population of <em>D. relictum</em> Mederos sp.&nbsp;nov. is isolated. <em>Dicranophragma relictum</em> Mederos sp.&nbsp;nov. is characterized by the following features: a general grey-to-greenish-grey coloration on its thorax and a dark-grey abdomen; wings more than four times longer than wide; pale-brown-to-yellowish tinted wings, with brown veins and a well-marked stigma; in the male genitalia the upper part of the aedeagus is acute when viewed laterally and is longer than the lower part. A key is provided for separating the three species of <em>Dicranophragma</em> known to be present in the Iberian Peninsula.</p> Jorge Mederos Sergi Gago Neus Brañas Floren Fadrique Berta Caballero-López Glòria Masó Copyright (c) 2020 Jorge Mederos, Sergi Gago, Neus Brañas, Floren Fadrique, Berta Caballero-López, Glòria Masó 2020-11-25 2020-11-25 726 109–121 109–121 10.5852/ejt.2020.724.1163 Two new species of planthoppers from India (Hemiptera: Auchenorrhyncha: Delphacidae) in the genera Parasogata and Eoeurysa <p>The genus <em>Parasogata</em> Zhou, Yang &amp; Chen, 2018 is here reported from India represented by the new species <em>Parasogata sexpartita</em> sp.&nbsp;nov. collected in a recent exploration and survey of delphacids from Nagaland in northeastern India. A second species of <em>Eoeurysa</em> Muir, 1913 from India, the new species <em>Eoeurysa sagittaria</em> sp.&nbsp;nov., was found in Rampur, Una, Himachal Pradesh. Both new species are described with illustrations, and a molecular identification is given with the mtCOI gene sequence. A modified key to species of the genera is also provided.</p> N Ramya Charles Bartlett Naresh M. Meshram Copyright (c) 2020 Ramya N., Charles Bartlett, Naresh M. Meshram 2020-11-23 2020-11-23 726 93 108 10.5852/ejt.2020.724.1161 Additions to the Swedish fauna of Diplazontinae (Hymenoptera: Ichneumonidae) with the descriptions of five new species <p>Although Sweden is a country with a comparatively well-known fauna, there are still many species that await discovery, especially in the boreal regions. In this study five new species of Diplazontinae, <em>Homotropus klopfsteinae</em> sp. nov., <em>Homotropus hellqvisti</em> sp. nov., <em>Homotropus mugerwai</em> sp. nov., <em>Homotropus riedeli</em> sp. nov. and <em>Woldstedtius aureotibialis</em> sp. nov., are described. <em>Sussaba roberti</em> Klopfstein, 2014 and <em>Homotropus megaspis</em> (Thomson, 1890) are reported for the first time from Sweden. Four of the new species are described from boreal areas, which highlights the need to further investigate the river- and seaside areas of the western taiga.</p> Niklas Johansson Copyright (c) 2020 Niklas Johansson 2020-11-20 2020-11-20 726 70–92 70–92 10.5852/ejt.2020.724.1159 First records and a new genus of comb-tailed spiders (Araneae: Hahniidae) from Thailand with comments on the six-eyed species of this family <p>The family Hahniidae is reported from Thailand for the first time. The genus <em>Hexamatia</em> gen.&nbsp;nov. and two new species, <em>Hexamatia seekhaow</em> gen. et sp. nov. and <em>Hahnia ngai </em>sp. nov., are described and illustrated. DNA sequences are provided for all the species reported here. The phylogenetic position of the novel genus <em>Hexamatia</em> gen. nov. and its relation to <em>Hahnia</em> are discussed. Based on these results, a new combination is proposed for <em>Hexamatia senaria</em> (Zhang, Li &amp; Zheng, 2011) gen. et comb. nov. = <em>Hahnia senaria</em>. Known distribution of the species <em>Hahnia saccata</em> Zhang, Li &amp; Zheng, 2011, originally described from China, is expanded. A brief review and notes on the taxonomy of the six-eyed hahniids are included.</p> Francisco Andrés Rivera-Quiroz Booppa Petcharad Jeremy A. Miller Copyright (c) 2020 Francisco Andrés Rivera-Quiroz, Booppa Petcharad, Jeremy A. Miller 2020-11-20 2020-11-20 726 51–69 51–69 10.5852/ejt.2020.724.1157 Onisimus turgidus (Sars, 1879) (Amphipoda, Uristidae), an overlooked amphipod from sea anemones in Northern Norway <p>Two Norwegian uristid amphipods, obligate associates of sea anemones, have for a long time been confused sub nomine&nbsp;<em>Onisimus normani</em>&nbsp;Sars, 1890. In reality this species only occurs in south Norway, while the north-Norwegian material belongs to <em>O. turgidus</em>&nbsp;(Sars, 1879), described from the Barents Sea and for a long time forgotten. This paper fully illustrates both species, gives a key, and provides data on their distribution and ecology.</p> Wim Vader Jan Roger Johnsen Anne Helene S. Tandberg Copyright (c) 2020 Wim Vader, Jan Roger Johnsen, Anne Helene S. Tandberg 2020-11-18 2020-11-18 726 34–50 34–50 10.5852/ejt.2020.724.1155 On eight species of the spider genus Synagelides Strand, 1906 from China (Araneae: Salticidae) <p>Six new species of <em>Synagelides</em> Strand, 1906 are diagnosed and described: <em>S.&nbsp;bohdanowiczi</em> sp.&nbsp;nov. (♂♀), <em>S.&nbsp;leigongensis</em> sp.&nbsp;nov. (♂♀), <em>S.&nbsp;logunovi</em> sp.&nbsp;nov. (♂♀), <em>S.&nbsp;subgambosus</em> sp.&nbsp;nov. (♂♀), <em>S.&nbsp;wuliangensis</em> sp.&nbsp;nov. (♂♀) and <em>S.&nbsp;xingdouensis</em> sp.&nbsp;nov. (♂♀). The female of <em>S.&nbsp;forkiforma</em> Yang, Zhu &amp; Song, 2007 and the male of <em>S.&nbsp; longus</em> Song &amp; Chai, 1992 are described for the first time. Photos of the habitus and copulatory organs, as well as a distributional map, are provided.</p> Cheng Wang Xiao-Qi Mi Muhammad Irfan Xian-Jin Peng Copyright (c) 2020 Cheng Wang, Xiao-Qi Mi, Muhammad Irfan, Xian-Jin Peng 2020-11-18 2020-11-18 726 1–33 1–33 10.5852/ejt.2020.724.1153 Two new nematode species of the genus Paratrilobus Micoletzky, 1922 (Nematoda, Triplonchida) from the water area of Lake Baikal (Russia) <p>This paper describes and illustrates two new nematode species of the genus <em>Paratrilobus</em> Micoletzky, 1922. The species <em>Paratrilobus tankhoyensis</em> sp.&nbsp;nov. was found at the estuary of the Pereyomnaya River (water area of Lake Baikal, near the Tankhoy railway station). <em>Paratrilobus tankhoyensis </em>sp.&nbsp;nov. is most similar to<em> P.&nbsp;expugnator </em>(Tsalolichin, 1976) in the body size, but differs in the comparatively thin body, shorter and thicker tail, shorter stoma and spicules. Another new species, <em>Paratrilobus aquaticus</em> sp.&nbsp;nov., was found in Posolsk Bank (natural underwater elevation of the bottom between the southern and central basins of Lake Baikal). The species is similar to <em>P.&nbsp;granulosus</em> Gagarin &amp;#38; Naumova, 2011 and <em>P.&nbsp;ultimus</em> (Tsalolichin, 1977) in the structure of the precloacal supplements. It differs from the former in the absence of crystalloids, a comparatively longer pharynx, longer stoma and outer labial setae as well as the absence of subterminal seta. It differs from the latter in a longer pharynx, stoma and longer outer labial setae as well as a longer and more slender tail. We also discuss diagnostic features of the males of the genus<em> Paratrilobus</em>.</p> Tatyana V. Naumova Vladimir G. Gagarin Copyright (c) 2020 Tatyana V. Naumova , Vladimir G. Gagarin 2020-11-16 2020-11-16 726 159 172 10.5852/ejt.2020.723.1151