A revision of the type material and historical specimens of brachyuran crabs collected from the late Miocene (Messinian) of Oran, Algeria, is proposed. These specimens were first described by Van Straelen (1937) as Maja arambourgi, Hyas oranensis, Calappa saheliensis, and Geryon latifrons. The reappraisal of the spider crab M. arambourgi allows us to assign it to the new genus Wahrania n. gen. Besides some peculiar morphological characters of Wahrania n. gen. lead us to propose the new subfamily Wahraniinae n. subfam. within the Epialtidae MacLeay, 1838, representing the second report of this family from the Miocene of the Mediterranean Basin. The new genus Parahyas n. gen. is erected to accommodate the spider crab H. oranensis. It is the sole Mediterranean fossil genus within the Oregoniidae Garth, 1958. The reappraisal of C. saheliensis allowed us to confirm its assignment to Calappa Weber, 1795, known in the Miocene fossil record with three species. Geryon latifrons is considered as a junior synonym of Chlinocephalus demissifrons Ristori, 1886. This synonymy results the first report from Africa of this species known to date from the Miocene and Plio-Pleistocene of Italy and the Miocene of Spain and Hungary. We also revise one very large isolated chela assigned to Cancer sp. by Van Straelen (1937), and we report some specimens of Cancer sismondai Meyer, 1843 collected by Camille Arambourg. Two new specimens collected by Léopold Geslin are assigned to Goneplax gulderi Bachmayer, 1953, representing the first record of the species in the southern Proto-Mediterranean Basin.
Crustacea, Epialtidae, Oregoniidae Calappidae, Euryplacidae, Goneplacidae, North Africa, Messinian, new subfamily, new genera, new combinations, new synonym