Bigalkenema namaquensis n.g., n. sp., is described from domestic sheep. The new genus belongs to the Trichostrongylidae. lt is closely related to the genus Longistrongylus le Roux, from which it is separated by its dorsal ray, bifurcated near its tip and not from its base, and in that the lateral bursal rays are divergent. Two species are placed in this genus: B. namaquensis n.g., n. sp., type species, and Bigalkenema sabie (Monnig, 1932) nov. comb. The genus Longistrongylus is restricted to the two species L. meyeri. le Roux. 1931 and L. albifrontis (Monnig, 1931 ). The species Longistrongylus schrenki is transferred to a closely related new genus Kobusi-nema, characterised by parallel postero-and medio-lateral rays and a dorsal ray split only towards its tip.