An annotated list of the millipede (Diplopoda) species described by Johann Carl Author Hollier, John Muséum d’histoire naturelle, C. P. 6434, CH- 1211 Genève 6, Switzerland. E-mail: john. hollier @ ville-ge. ch john.hollier@ville-ge.ch Author Stöckli, Eduard Naturhistorisches Museum Basel, Augustinergasse 2, CH- 4051 Basel, Switzerland. E-mail: eduard. stoeckli @ bs. ch eduard.stoeckli@bs.ch Author Wesener, Thomas Zoologisches Forschungsmuseum Alexander Koenig, Leibniz Institute for Animal Biodiversity, Adenauerallee 160, D- 53113 Bonn, Germany. E-mail: T. Wesener @ leibniz-zfmk. de esener@leibniz-zfmk.de Author Mesibov, Robert West Ulverstone, Tasmania, Australia 7315. E-mail: robert. mesibov @ gmail. com robert.mesibov@gmail.com Author Decker, Peter Senckenberg Museum für Naturkunde Görlitz, Department of Soil Zoology, Am Museum 1, D- 02826 Görlitz, Germany. E-mail: peter. decker @ senckenberg. de peter.decker@senckenberg.de Author Sierwald, Petra Field Museum of Natural History, 1400 S. Lake Shore Drive, Chicago, IL 60605, USA. E-mail: psierwald @ fmnh. org psierwald@fmnh.org text Revue suisse de Zoologie 2020 2020-06-04 127 1 183 240 http://dx.doi.org/10.35929/rsz.0015 journal article 10.35929/RSZ.0015 0035-418 5743454 helicogonus Carl, 1941b: 679-682 , figs 173-178 [ Thyropygus ]. Nilgiris: Coonoor, 1600 m , Djungel, unter Laub, auf Humus, 24.XII.1926 . One ♂ and one ♀ . The MHNG collection contains two specimens in alcohol in one vial (MHNG-ARTO-14256). Both specimens are broken, and are accompanied by a smaller vial containing a head, gonopods and other fragments. The data label has “Kleiner Djungel 24.XII , unterhalb Coonoor” written on it, indicating that the specimens are syntypes . Gnomognathus helicogonus (Carl, 1941) , Harpagophoridae