Semon, op. cit. p. 115.
For a list of the more important papers on Protopterus, see Boulenger, Les Poissons du Bassin du Congo, Bruxelles, 1901, pp. 40-42.
Traquair, Rep. Brit. Ass. 1871 (2), p. 143; Boulenger, P.Z.S. 1891, p. 147.
Newton Parker, Trans. Roy. Irish Acad. xxx. 1892, p. 201.
Trans. Zool. Soc. xvi. Pt. ii. 1901, p. 119.