Crossodonthina Yosii 1954

Identification key to the species of Crossodonthina * 1 Eyes 2+2............................................................................................ 2 - Eyes 3+3............................................................................................ 6 2 Tubercle Oc with 2 chaetae.......................................... C. hainana Xiong, Chen & Yin, 2005 (China) - Tubercle Oc with 3 chaetae............................................................................. 3 3 Tubercles Di fused on Abd. V ............................................ C. bidentata Luo & Chen, 2009 (China) - Tubercles Di separated on Abd. V ........................................................................ 4 4 Mandible with 1 basal tooth.............................................. C. montana Lee & Kim, 1990 (Taiwan) - Mandible with 2 or more basal teeth...................................................................... 5 5 Mandible with 2 or more basal teeth. Eyes black................ C. langshanensis Hu, Jiang C. & Jiang J.G., 2019 (China) - Mandible with 5 basal teeth. Eyes unpigmented......................... C. quadridentata Jiang & Wang, 2024 (China) 6 Cephalic O chaeta absent............................................................................... 7 - Cephalic O chaeta present.............................................................................. 8 7 Four cephalic tubercles, 2 Di and 2 De, fused into a single median structure........ C. altamontana Yoshii, 1981 (Malaysia) - Four cephalic tubercles, 2 Di and 2 De, not fused with each other.................... C. formosana Yosii, 1965 (Taiwan) 8 Tubercles Di, De, Dl on Th. I with 3, 2, 3 chaetae, respectively................ C. radiata (Salmon, 1941) (New Zealand) - Tubercles Di, De, Dl on Th. I with 1, 2, 1 chaetae, respectively................................................. 9 9 Tubercles De and Dl fused on Abd. V .................................................................... 10 - Tubercles De and Dl separated on Abd. V ................................................................. 12 10 An additional sensory chaeta present on tubercle L of Abd. IV............................. C. leodeus sp. nov. (Japan) - An additional sensory chaeta absent on tubercle L of Abd. IV................................................. 11 11 Di2 chaetae on Th. II–Abd. V as microchaeta. Body tubercles poorly developed: Di tubercles on Th. I–Abd. IV reduced................................................................... C. koreana Yosii & Lee, 1963 (Korea & Japan) - Di2 chaetae on Th. II–Abd. V as macro- or mesochaeta. Body tubercles spherical.... C. tridentiens Yue & Yin, 1999 (China) 12 De2 chaetae on head as macrochaeta.......................................... C. alatoserrata Yosii, 1965 (Taiwan) - De2 chaetae on head as microchaeta or absent............................................................. 13 13 An additional sensory chaeta present on tubercle L of Abd. IV................................................. 14 - An additional sensory chaeta absent on tubercle L of Abd. IV................................................. 15 14 An additional sensory chaeta present on tubercle L of Abd. I– III .............. C. acuminata Jiang & Wang, 2021 (China) - An additional sensory chaeta absent on tubercle L of Abd. I– III ...................... C. nipponica Yosii, 1954 (Japan) 15 An additional sensory chaeta present on tubercle L of Abd. I– III ............................................... 16 - An additional sensory chaeta absent on tubercle L of Abd. I– III ............................................... 18 16 Maxillary head with cilia. Macrochaeta pointed. Dorsal side of Th. I red in living specimen......................... 17 - Maxillary head without cilia. Macrochaeta blunt. Dorsal side of Th. I yellow or white in living specimen.......................................................................... C. elegans Kasai, Tanaka & Sawahata, 2023 (Japan) 17 Mandible with 3 rami and 5 basal teeth. Unguis inner tooth often with 1–3 tiny basal denticules.................................................................................. C. tiantongshana Xiong, Chen & Yin, 2005 (China) - Mandible with 6 rami and 3 basal teeth. Unguis inner tooth without basal denticules............................................................................ C. laterisensillata Ohira, Kataoka, Tanooka & Nakamori, 2022 (Japan) 18 Five chaetae (4+s) on tubercle De of Th. II. Eyes black......................... C. choui Jiang & Zhang, 2012 (China) - Four chaetae (3+s) on tubercle De of Th. II. Eyes unpigmented.................. C. clavata Jiang & Wang, 2021 (China) *This key is partially based on Luo & Chen (2009), Jiang & Wang (2021) and Kasai et al. (2023).