A Taxonomic Revision of the Trichostrongyloid Nematode Parasites of the Echidna, Tachyglossus Aculeatus (Monotremata).

The trichostrongyloid nematodes of the echidna, Tachyglossus aculeatus (Shaw), are revised and redescribed. Species formerly placed in the genus Nicollina Baylis are redistributed among three genera Nicollina, Tachynema, gen. nov., and Tasmanema, gen. nov., distinguished by the arrangement of the bursal rays, presence of lips and presence of a corona radiata. Species admitted to Nicollina are: N. tachyglossi (Baylis) (type-species); N. cameroni Thomas; N. echidnae (Baylis); N. patriciae, sp. nov.; N. queenslandensis, sp. nov.; N. ridei Inglis; N, spearei, sp. nov. Two species are placed in the genus Tachynema: T. baylisi (Mawson), comb. nov. (type-species); T. spratti, sp. nov. The genus Tasmanema contains one species: T mundayi (Mawson), comb. nov. (type-species). Evidence is presented that nematode species occur in restricted areas of the small intestine of the host and that the dominant nematode species varies from host to host. Vicariant species of nematode occur in the different geographic regions of the continent.