FREELIVING AND PLANT PARASITIC NEMATODES FROM SPITZBERGEN, COLLECTED BY MR. H. VAN ROSSEN Author P. A. A. LOOF Department of Hematology, Agricultural University, Wageningen, The Netherlands text Mededelingen Landbouwhogeschool Wageningen 1971 1971-12-31 71 1 86 journal article 10.5281/zenodo.8152982 dc936e39-ea56-4501-b5ba-a24d055276c8 8152982 85C9CB49-EEA1-467B-ACC7-7C11B9EDEEAD Teratocephalus decarinus Anderson, 1969 ( Fig. 6 , A -C) Dimensions often females: L = 0. 52- 0.56 mm ; a = 23 -24; b = 3.7 -3.9; c = 4.8 - 5.7; V = 1 3 _1 8 54 -5 8. First two annules behind lip region small and compressed; the next four to six are directed anteriad. Vulva depressed; a short postvulval sac is present. The tail measures 9-11 anal body diameters; vulva-anus distance is 138 -145 % of tail length. Samples 62, 66 and 67. The distinction between this species and T.costatus Andrässy, 1958 is somewhat problematical. A population from New Galloway, Scotland , is clearly T. costatus because of the shape of the neck annules, but the cervical expansion characteristic of that species is absent, as in T. decarinus . Specimens from the island of Terschelling, The Netherlands , have the characters of T. decarinus , but a juvenile has the neck annules shaped as in T. costatus . Clear differences in tail tip and shape of body annules could not be found between all these populations. So for the moment the only established difference is the shape of the neck annules: directed anteriad in decarinus , not so in costatus . Whether this difference is really of specific importance remains to be seen. T. decarinus is now known from northern Canada , Spitzbergen, Sweden (Flommen) and Scotland ; T.costatus from Bulgaria and the Netherlands . The species has also been reported from Paraguay (Andrässy, 1968).