Cephalobium magdalensis n.sp.(Rhabditida: Diplogasteridae) found in Magdalena, Buenos Aires, and Cruznema lincolnensis n.sp.(Rhabditida: Rhabditidae) found in Lincoln, Buenos Aires, parasitizing the cricket Gryllodes laplatae (Orthoptera: Gryllidae) are described and illustrated.
C.magdalensis Chews n.sp.is characterized by having the excretory pore between the pseudobulb and the basal bulb and seven pairs of postanal papillae in the male.C.
lincolnensis n.sp.can be distiguished by having meanly two Wardrobe Door Hardware pairs of preanal papillae, one pair of adanal papillae and six pairs of postanal papillae in the male.