Hyperolius acuticephalus Ahl, 1931a: 131.

Tillack, Frank, Ruiter, Ronald de & Roedel, Mark-Oliver, 2021, A type catalogue of the reed frogs (Amphibia, Anura, Hyperoliidae) in the collection of the Museum fuer Naturkunde Berlin (ZMB) with comments on historical collectors and expeditions, Zoosystematics and Evolution 97 (2), pp. 407-450 : 407

Hyperolius acuticephalus Ahl, 1931a: 131.

Holotype.

ZMB 30999; "Ngoto, Lobajegebiet" [ Kembé, Basse-Kotto Prefecture, Central African Republic]; coll. Günther Theodor Tessmann, 30.X.1913.

Present name.

Hyperolius acuticephalus Ahl, 1931.

Remarks.

Depicted in Ahl (1931b: 419, fig. 291). The German botanist, ethnologist and explorer Tessmann travelled to Cameroon in 1904, where he worked until 1905 for the West African plantation company Bibundi as a supervisor on a cocoa plantation. Afterwards he travelled to the Cameroon Hinterland [ ‚Hinterland‘ is a term in the colonial literature, used in various languages; it does not specify a specific geographic region but refers generally to regions being away from the coast or provincial towns] and to Yaoundé and founded his own plantation in the border area between German-Cameroon and Spanish-Guinea. From 1907 to 1909 he was the head of the “Lübecker Pangwe-Expedition" to South Cameroon and Equatorial Guinea and in 1913 he led an expedition to "Neu Kamerun". During the First World War he fled to Spanish Guinea and was interned by the Spanish on Fernando Pó [Bioko]. Later, he turned to South America, travelled through Peru, and emigrated to Brazil in 1936, where he settled in the state of Paraná and got a position at the Museu Paranaense. During his stay in Africa he collected large numbers of zoological, botanical and ethnological objects, most of which were sent to the museums in Berlin and Lübeck ( Dinslage and Templin 2012; Dinslage 2015; Templin 2015).

Hyperolius acuticephalus could be conspecific with either H. igbettensis Schiøtz, 1963 or H. adsperus Peters, 1877. Type locality and shape of head better fit H. igebettensis (fide Channing et al. 2013); concerning webbing of feet H. acuticephalus is intermediate between H. igbettensis and H. adspersus (fide Channing et al. 2013); the ratio of head width/snout-vent length speaks in favor of H. adspersus (fide Amiet 2012); and the ratio of head length/head width points again to H. igbettensis (fide Amiet 2012); finally the value for the length of the snout/head width surpasses both H. igebettensis and H. adspersus .