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 Criconemoides hemisphaericaudatus Wu, 1965 (Fig. 13, A -B). One female. Dimensions: L = 0.51 mm ; a = 13; b = 3.4; c = 28; V = 5493. Spear length = 84 pi. Rex = 36; RV = 10; Ran = 6; R = 116. Tail very bluntly rounded, posterior end of body tapering hardly, almost cylindroid. The annules 98 -115 show lateral indentations. There are occasional anastomoses, one to three together. Head end rounded, submedian lobes very small. The posterior margin of the annules is very finely crenate. Vulva apparently slightly open; the vagina runs almost transversely in its distal part. The posterior edge of the prevulvar annule is modified slightly, suggesting a small ornamentation on the anterior vulva lip in agreement with Wu's fig. 14. Two very small juveniles (L -2 or L -3), one damaged. L = 0.23 mm ; spear = 37 -40 ji.; gonad primordium = l i p.; Rex = 42, R = 127 (n = 1). Annules crenate with rather many anastomoses. This species is very close to C.morgensis (Hofmänner & Menzel, 1914) with which it was considered identical by de Grisse, 1968. However, I prefer to keep it apart because of the shape of the posterior body end (in morgensis tapering, truncate) and the appearance of the vulva: in morgensis it is distinctly closed in lateral view, situated on the middle of the annule; in hemisphaericaudatus it appears slightly open in lateral view (ventral view shows it to be closed really) and lies between two annules. In morgensis the vagina runs obliquely to the vulva, in hemisphaericaudatus almost transversely. Finally the crenation of the posterior margins of the annules appears more coarse in morgensis than in hemisphaericaudatus . Whether C. annulatus Taylor, 1936 is identical with morgensis or with hemisphaericaudatus cannot be decided for the moment: vagina direction suggests the former, tail shape the latter (Cf. Raski & Golden, 1966, fig. 4 D- E). Female in sample 26; juveniles in 26 and 62.