1–4 Dorsal view of head 1 Sternolophus acutipenis a width of clypeus at anterior margin of eyes 2 S. jaechi 3 S. marginicollis a centre of frontoclypeal suture 4 S. solieri a deeper punctures near the basal margin of labrum b paired antero-lateral groups of punctures on the clypeus (Nasserzadeh and Komarek 2017) 5–7 Ventral view of head 5 Sternolophus acutipenis 6 S. angustatus 7 S. decens a maxilla b pubescent area on submentum c bare area of submentum d base of mentum 8 Maxillary palpus of Sternolophus acutipenis a–c length of palpus segments (Nasserzadeh and Komarek 2017) 9–13 Prosternal carina 9 Sternolophus acutipenis 10 S. angustatus 11 S. decens 12 S. jaechi 13 S. solieri (Nasserzadeh and Komarek 2017).

  Part of: Nasserzadeh H, Alipanah H, Gilasian E (2017) Phylogenetic study of the genus Sternolophus Solier (Coleoptera, Hydrophilidae) based on adult morphology. ZooKeys 712: 69-85. https://doi.org/10.3897/zookeys.712.14085