[Studies on the Echinonematinae (Nematoda)]

Complementary data on the Echinonematinae have been obtained by study of "The Australian Helminth Collection, formerly the Univeristy of Adelaide, Department of Zoology Helminth Collection, currently housed in the South Australial Museum", and by a morphological and biological study of new material. The Echinonematinae actually known are the following: -- Seurechina chaneeti n. gen., n. sp., parasite of Dasyurus hallucatus (West Australia) does not have large cephalic hooks but about 50 rings of spines covering the anterior fifth of the body. -- Inglechina australis (Inglis and Mawson, 1967) n. gen., n. comb., a parasite of Sminthopsis crassicaudata (South Australia) has 3 rings of large cephalic hooks, but no special cuticular structures in the cervical region. -- Echinonema v. Linstow, 1898, is a parasite of Dasyuridae and Peramelidae. The head bears 3 rings of large hooks and the cervical region about 15 rings of hooks of medium size. The females are monodelphic. -- E. edmondsi n. sp. from Dasyurus hallucatus (Northern Territory) has a long oesophagus and cephalic hooks of the first circle longer than those of the second one. -- E. cinctum von Linstow, 1898, from Isoodon macarourus (N.E. of Australia) has a long oesophagus and cephalic hooks of the second circle longer than those of the first one. -- E. meridionalis n. sp., from Isoodon obesulus (S.E. of Australia) has a short oesophagus and precloacal spines in males. -- E. inglisi n. sp. (= E. cinctum sensu Inglis, 1967), from Isoodon obesulus (Western Australia) has a short oesophagus and no precloacal spines in males. -- E. spp.: the different shapes of the tail in males are illustrated for E. sp. from Perameles and for E. sp. from Isoodon of Tasmania. -- E. cinctum developed experimentally in the Orthoptera Locusta migratoria. The cellular reactions (simple haemocytic capsule) and the morphology of the infective stage are primitive and seem to be intermediate between the Subuluroid and Seuratoid types. The Echinonematinae are interpreted as having been derived from ancestors close to Seuratum (parasite of bats), which adapted to a particular group of Australian marsupials ad evolved a characteristic structure for attachment to host tissues. However they have retained a primitive biology.