Martadamsonius aculeatus sp. n. is described from the gut of Spirostreptus timotheus from Zaire. It differs from M.duponti Van Waerebeke, 1987 in having virtually straight spicules as opposed to distinctly arcuate, eight vs four rows of cervical spines in the female; lateral alae extending to the tail region in the female (terminating prior to the vulva in M. duponti) and the development of a predominantly smooth, cuticular field located laterally on the male tail. From M. moramangiensis Van Waerebeke, 1987, it differs in lacking a small ventral notch on the straight edge of the gubernaculum, having fewer and less well developed cervical spines in the male, lateral alae extending to the tail region in the female (terminating prior to the vulva in M. moramangiensis), development of a predominantly smooth, cuticular field located laterally on the male tail and in having longer spicules (285 vs 227 μm). M. gubgibbosus (Dollfus, 1964) comb. n. is proposed and regarded as a species inquirenda. Waerebekeia debbiae sp. n., from the gut of a spirostreptid diplopod from Ivory Coast, is described and illustrated with the aid of scanning electron microscopy (SEM). The new species is characterised by: female lacking cuticularised pieces around the oral aperture, presence of minute spinelets on the somatic striae, male oral aperture laterally elongate, presence of subrectangular blocks of cuticle on the male striae, long, adpressed spicules with fine cuticular striae, shallowly keel-shaped gubernaculum with a dorsal hole, fifteen pairs of copulatory papillae with two pairs subdorsal in position, one being adcloacal and the other near the caudal appendage. The species is distinguished from the type and only other nominal species in the genus by the gubernaculum having a different shape and shallower keel, the longer male tail and longer spicules. Additional data from two Ivory Coast populations of Gilsonema venardi, together with SEM studies, supplement the original description.