The mostly cavernicolous millipede genus Stygiiulus Verhoeff, 1929, stat. nov.: taxonomy, distribution and phylogenetic relationships (Diplopoda, Julida, Julidae) Author Vagalinski, Boyan CF6A5691-5C32-4CFF-9EB6-045DEB16F289 Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin Street, 1113, Sofia, Bulgaria. boyanv84@gmail.com Author Borissov, Simeon C035E1AC-D4FB-4A3F-8B38-5D38A9665E88 Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin Street, 1113, Sofia, Bulgaria. borissovsb@gmail.com Author Bobeva, Aneliya 0F4EA315-46BE-49AC-8FB4-CF710C5B2451 Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin Street, 1113, Sofia, Bulgaria. aneliabobeva@gmail.com Author Canciani, Giacomo 4BB21FD2-15C8-44BD-907A-4498D7D02A15 Jamarski Klub Kraški Krti / G. S. Talpe del Carso, loc. San Michele del Carso / Vrh, I- 34070 Savogna d’Isonzo (GO), Italy. & Associazione Speleologica Forum Julii Speleo, Via Carraria 99, I- 33043 Cividale del Friuli (UD), Italy. giacomo.canciani90@gmail.com Author Antić, Dragan Ž. 2368C980-2042-4137-998D-8C91E4337185 University of Belgrade - Faculty of Biology, Institute of Zoology, Studentski Trg 16, 11000 Belgrade, Serbia. & Serbian Biospeleological Society, Trg Dositeja Obradovića 2, 21000 Novi Sad, Serbia. dragan.antic@bio.bg.ac.rs text European Journal of Taxonomy 2022 2022-02-28 798 30 69 http://dx.doi.org/10.5852/ejt.2022.798.1669 journal article 20422 10.5852/ejt.2022.798.1669 31fec661-5dac-4626-856d-4ba4680efee7 2118-9773 6323002 50692D26-A41C-4F85-B207-A6747FD07470 Stygiiulus tobias (Berlese, 1886) comb. nov. Figs 10F , 11D , 13 Julus ( Typhloiulus ) Tobias Berlese, 1886: 98–99 , tab. XIII, figs 20–23 . Typhloiulus ( Iulus, Mesoporoiulus ) Tobia ( tobias ) – Manfredi 1932: 81 . Typhloiulus tobias – Wolf 1934 –38: 516. — Vagalinski et al. 2015: 345–346 . Typhloiulis (sic!) tobias – Boldori 1936: 113 . Typhloiulus Tobia (sic!) – Boldori 1937: 11 . Typhloiulus ( Mesoporoiulus ) tobias – Verhoeff 1930: 16–17 , fig. 3. — Strasser 1962: 38–39 , figs 11f, 45–46. Typhloiulus Tobias – Conci 1951: 44 . Typhloiulus tobias var. fuscus Manfredi, 1953a: 139 . ? Typhloiulus tobias pygmaeus Manfredi, 1953b: 100 . Typhloiulus tobias fuscus – Manfredi 1953b: 101 . Diagnosis A species of Stygiiulus stat. nov. with normal mouthparts. Clearly distinguishable from congeners by the very distinctive structure of the opisthomere ( Fig. 10F ) including a right- to acute-angled posterior hump pointing distad, a large, (sometimes) bipartite velum (with a posteriorly positioned distal outgrowth (do), this being much less prominent than in S. insularis comb. nov. and S. seewaldi comb. nov. ), with the main part being mostly smooth (barely serrated), and a solenomere distally forming a stout anterior and a much more slender posterior branch, both apically finely ciliate; some specimens with a minute third thumb-like branch basally to the posterior branch. In addition, this species (except for its dubious subspecies T. t. pygmaeus , see below) differs from all other Stygiiulus stat. nov. species by the presence of a very long and upwards curved epiproct. Material examined ITALY • 2 ♂♂ , 1 ♀ ; Veneto , Altopiano dei Sette Comuni , Vastagna (VI), Grotta [cave] del Subiolo (135 V/VI); 169 m a.s.l. ; 4 Mar. 1990 ; G. Peretto and E. Piva leg.; H. Enghoff det. 2013; NHMD . Descriptive notes ANTENNAE. 2.2–2.4 times as long as head and 1.65–1.7 as long as H in males, and 1.9–2 and 1.3– 1.4 times, respectively, in females; antennomere 5 2.6–2.9 times as long as broad; antennomeres 2, 3 and 5 subequal in length, slightly longer than 4, and 1.4–1.5 times as long as 6. Fig. 10. Left gonopods of species of Stygiiulus stat. nov. , mesal views. A . S. ausugi (Manfredi, 1953) comb.nov. ,topotype♂(NHMD). B . S.illyricus ( Verhoeff,1929 ) comb.nov. ,redrawn from Verhoeff (1929) . C . S. insularis ( Strasser, 1938 ) comb. nov. , redrawn from Antić et al. (2018) . D . S. maximus ( Verhoeff, 1929 ) comb. nov. , redrawn from Verhoeff (1930) . E . S. seewaldi ( Strasser, 1967 ) comb. nov. , redrawn and modified from Strasser (1967) . F . S. tobias (Berlese, 1886) comb. nov. , ♂ from Grotta [Cave] del Subiolo (NHMD). Abbreviations: do = distal outgrowth of velum. Drawn not to scale. TARSUS OF MID- BODY LEGS. 1.8–1.9 times as long as tibia and 2.8–4.3 times as long as apical claw. Midbody legs ca 1.25 times as long as H in males, and equal in length in females. FEMALE SEXUAL CHARACTERS. Leg-pairs 1 and 2 considerably thicker and shorter than following legs. Vulva ( Fig. 11D ) nearly symmetric; bursa slightly compressed in the sagittal plane; each valve distally with one vertical row of several setae; a similar row present on each side sclerite; operculum (op) very thick, subconical, i.e., tapering to a distinct blunt apex, exceeding bursa by ca 1 ⁄ 5 of total height of vulva, distally with a dense bunch of setae each side. Receptaculum seminis consisting of two long and narrow, closely adjacent tubes of equal length – a twisted lateral one (lt) leading to a small piriform ampulla (la), and a mostly straight mesal one (mt) ending in a somewhat larger ovoid ampulla (ma). Distribution Known from numerous caves and one epigean locality in the central Venetian Prealps, as well as from several caves in Monti Lessini (extreme south of the Venetian Prealps). Also known from two caves on the southern slopes of Dolomiti ( Fig. 13 , white squares). Remarks In the past, this taxon was treated as a member of Mesoporoiulus Verhoeff, 1905 . Vagalinski et al. (2015) hypothesized it could be a somewhat deviating member of Stygiiulus . Here we fully confirm this assumption and formally transfer tobias to the genus Stygiiulus . The subspecies S. t. pygmaeus (Manfredi, 1953) comb. nov. has already caught the attention of Strasser (1962) . On page 60 of the latter work, the author commented on the significant size difference between pygmaeus ( 23 mm of length) and the typical tobias ( 50–67 mm of length), and also emphasized the apparent confusion of Manfredi (1953b) regarding the gonopods of her newly described subspecies, which she stated to match well (along with most other characters) to the descriptions of tobias given by both Attems (1927) and Verhoeff (1930) . In fact, what Attems (1927) recorded and depicted was S. maximus comb. nov. (see Remark under the latter species). The short and straight epiproct in pygmaeus (as originally described), unlike the long and upwards curved process in the typical form, adds further uncertainty about the identity of Manfredi’s subspecies. We agree with Strasser’s (1962) opinion that pygmaeus most likely represents a separate species. However, its status can only be resolved after examination of type or topotype material. The gonopods of the two presently examined males from Grotta del Subiolo differ fromVerhoeff’s(1930) drawings based on material from Grotta Parolini near Vastagna and/or “Bus de la Bela” near San Donato, prov. Belluno, by a blunt and finely serrated, rather than tapering and ciliate, posterior part of velum, and by an apically tri- instead of bipartite solenomere. In Grotta della Bigonda, this species lives in sympatry with S. ausugi comb. nov.