Genus Cerhomalus Quedenfeldt, 1884
Type species: Cerhomalus mechowi Quedenfeldt, 1984, by monotypy.
The largest orphnines (body length 15–22 mm). Colour uniformly dark brown to black. Clypeus of both sexes with a transversal keel, higher and apically bilobate in males and lower but distinct in females. Pronotal disc of males more or less depressed, sometimes slightly excavated, but distinct pronotal lateral processes always absent. Elytra convex, without ridges, with humeral umbones. Elytral surface sparsely covered with rounded punctures; punctures arranged in longitudinal striae, which are more distinct on disc. Protibiae with 3 strong outer teeth similar in both sexes. Apical protibial spur absent in males. Middle and posterior legs similar in shape; posterior femora and tibiae about 1/8 longer than middle ones. Parameres symmetrical, not setose apically, very wide in lateral view; inner sides of parameres with longitudinal excavations in 3 species. Ventroapical part of phallobase strongly sclerotized, in shape of 2 incompletely separated sclerites.
Female differs from male in having a relatively smaller, convex pronotum without tubercles and only with a small depression medially, frontoclypeus with much smaller, low keel not bimodal apically, protibial spur, and pygidium with rounded apex.
Species composition. The genus comprises four species.
Distribution. The genus occurs in Central and West Africa with the majority of records from the Congo Basin.
Frolov, A.V. & Akhmetova, L.A. (2021) Taxonomic revision of the Afrotropical scarab beetle genus Cerhomalus Quedenfeldt, 1884 (Coleoptera: Scarabaeidae: Orphninae). European Journal of Taxonomy, 739, 36–50.
Petrovitz, R. (1971) Beitrag zur Kenntnis der Gattung Orphnus M'Leay (Orphninae, Scarabaeidae, Coleoptera). Revue de Zoologie et Botanique Africaine, 84, 1-46.
Quedenfeldt, G. (1884) Verzeichniss der von Herrn Major a. D. von Mechow in Angola und am Quango-Strom 1878-1881 gesammelten Pectinicornen und Lamellicornen. Berliner Entomologische Zeitschrift, 28, 265-340.