A critical revision of the churchill snoutfish, genus Petrocephalus Marcusen, 1854 (Actinopterygii: Teleostei: Mormyridae), from southern and eastern Africa, with the recognition of Petrocephalus tanensis, and the description of five new species. Journal of Natural History, 46(35-36) 2012: 2179-2258. 2238 [Zoological Record Volume 149]