[New nematodes of the genus Trichospirura Smith and Chitwood, 1967, in Malaysia. Remarks on the evolution of the family Rhabdochonidae (author's transl)].

Description of Trichospirura willmottae n. sp. parasite of the salivary ducts of Tupaia glis and T. sp. (single virgin female) parasite of the intestine of Myotis mystacinus in Malaysia. The two species are very closely related to the type species, a parasite of the pancreatic ducts of brasilian Primates, and can be differentiated mainly by the mensurations of the posterior extremities of the bodies. While the genus Rhabdochoma, parasite of the intestine of fresh-water fishes, underwent a very similar, but more or less pronounced, morphological evolution, it became adapted to many different hosts: Sea-fishes, Saurians, Mammals and to many locations. This evolutionary line includes six genera; Trichospirura, the only parasite in Mammals, is one of the more evolved. Some remarks are made on the host-distribution of Trichospirura, on the relationships between Rabdochonidae and Cystidicolidae and on the osmo-excretory apparatus of Trichospirura. The hypertrophy of this apparatus, which could be the consequence of the passage during the course of evolution from aquatic to terrestrial life, is comparable to that of the Pneumospirurinae.