The family Amphiliidae includes about 66 species of generally small Afro-tropical catfishes, known commonly as mountain catfishes (Skelton 2001) or loach catfishes (Nelson 1994, 2006; Berra 2001). The species are distributed from the Senegal River in the West throughout coastal West Africa, West Central Africa, the Congo basin, the Nile and East African coastal rivers from the Webi-Shebeli to the Mkomaas River system in South Africa (Berra 2001, Lévêque 1997, Skelton 2001). Diogo (2003) provides a recent review and analysis of the anatomy, phylogeny and taxonomy of the Amphiliidae indicating that there are at least three major lineages that warrant sub-familial status, viz., the Amphiliinae , the Leptoglanidinae , and the Doumeinae . Diogo’s (2003) account gives detailed character diagnoses of these sub-families.
Amphiliids are small (the largest species reach to about 200 mm SL) benthic riverine catfishes with a wide range of body form from soft-bodied to slender, firm-bodied and highly streamlined forms, some with bony plates along the body. Amphiliid catfishes are poorly known from WCA where representatives of two sub-families, the Amphiliinae and the Doumeinae occur. The Amphiliinae are more generalized soft-bodied forms with two genera in the WCA region, Amphilius Günther , and Paramphilius Pellegrin . Amphilius from the WCA include A. longirostris (Boulenger, 1901) , A. pulcher Pellegrin, 1929 , and A. nigricaudatus Pellegrin, 1909 . Amphilius baudoni Pellegrin, 1928 was described from the region but is shown here to be a species of Paramphilius , a genus that includes three species from West Africa (Skelton et al., 2003) and Paramphilius goodi Harry, 1953 from WCA. Four new species of Amphilius are recognized and described in this paper.
Doumeine amphiliids are mostly slender and streamlined, well adapted to living in fast flowing currents. Their axial skeleton is progressively modified in the different species forming, in most genera, linear series of bony ridges or ‘plates’ along the body. Modified vertebrae are tightly inter-connected and bear stout bi-lateral dorsal and ventral flanges that, in genera other than Doumea Sauvage , expand distally to form linear series of bony plates exposed at the body surface. Two of the five doumeine genera, Doumea , and Phractura Boulenger , occur in the West Central African region. The known and described Doumea from the WCA include D. typica Sauvage, 1878 and D. thysi Skelton, 1989 . An additional two species are described herein. Skelton (2007) recognizes four species of Phractura in the WCA region, namely P. brevicauda Boulenger, 1911 , P. longicauda Boulenger, 1903 , P. gladysae Pellegrin, 1931 and one new species as described herein.
