Molecular phylogenetics facilitates the first historical biogeographic analysis of the hammerhead worms (Platyhelminthes: Tricladida: Bipaliinae), with the description of twelve new species and two new genera Author Solà, Eduard 0000-0003-1848-4085 eduardsola@ub.edu Author Sluys, Ronald 0000-0002-9776-3471 luys@naturalis.nl Author Riutort, Marta 0000-0003-1848-4085 eduardsola@ub.edu Author Kawakatsu, Masaharu 0000-0003-1848-4085 eduardsola@ub.edu text Zootaxa 2023 2023-08-18 5335 1 1 77 http://dx.doi.org/10.11646/zootaxa.5335.1.1 journal article 276875 10.11646/zootaxa.5335.1.1 93074190-36cb-467e-a6ef-103ac5e13f4b 1175-5326 8261375 E4E9FD1D-1923-416E-A5B5-4AC62A4F5DCD Umbotectum Solà & Sluys , gen. nov. Diagnosis Bipaliinae with an elongated body and a lunate or sickle-shaped head with auricles that can be notably elongated and recurved. Conical penis papilla containing a comparatively broad ejaculatory duct. Sperm ducts opening into the antero-ventral section of the bulbar cavity or seminal vesicle, the wall of the latter being highly folded. Dorsal wall of the common atrium with the shape of a broad, upside-down dome. Large, spherical and muscularized glands, secretory reservoirs, or glandular crypts located within the parenchyma of the hemispherical roof of the common atrium, being arranged concentrically as a kind of wreath around the openings of the female genital duct and the male atrium. The bulb of each of these glands is provided with a narrow lumen that via a slit-like ventral portion opens into the common atrium.