Head appendages of Spencerhydrus species, instar I 5 S. latecinctus, right antenna, dorsal aspect 6 S. latecinctus, left antenna, ventral aspect 7 S. pulchellus, right antenna, dorsal aspect 8 S. pulchellus, left antenna, ventral aspect 9 S. latecinctus, right mandible, dorsal aspect 10 S. pulchellus, right mandible, dorsal aspect 11 S. latecinctus, right maxilla, dorsal aspect 12 S. latecinctus, left maxilla, ventral aspect 13 S. pulchellus, right maxilla, dorsal aspect 14 S. pulchellus, left maxilla, ventral aspect. Numbers and lowercase letters indicate primary setae and pores, respectively. Additional setae and pores not labelled. Abbreviations: A1–4: antennomeres 1–4; AN: antenna; MN: mandible; MP1–3: maxillary palpomeres 1–3; MX: maxilla; PPF: palpifer; SP: spinula. Scale bar: 0.30 mm.

  Part of: Michat MC, Alarie Y, Watts CHS (2019) Dealing with a hairy beast–larval morphology and chaetotaxy of the Australian endemic diving beetle genus Spencerhydrus (Coleoptera, Dytiscidae, Cybistrini). ZooKeys 884: 53-67. https://doi.org/10.3897/zookeys.884.38391