Terrestrial nematodes from Jan Mayen Author Allgén, C. A. text Annals and Magazine of Natural History 1953 12 6 665 688 journal article 10.1080/00222935308654469 10811051 Monhystera macrura de Man. de Man, 1884 , p. 39, pl. iii, figs. 9, 9 a-d. Dimensions.-Body-length= 0.764 mm ., max. width=0.0 2 5 mm ., oesophagus = 0.148 mm ., tail= 0.197 mm ., v u l v a = 0.452 mm ., α =30.56, β =5.16, γ=3.88, V =59.16 per cent. Body -length=0.6 9 5 mm ., max. width - -0.0 2 1 mm ., (esophagus== 0.148 mm ., t a i l=0.1 8 0 mm., vulva= 0.4 2 0 mm., α=33.095, β=4.7 0, µ=3.86, V =60.43 per cent. In contrast t o Micoletzky, who regards this species as synonymous with M. wdgaris de Man , it m a y be remarked that M. macrura differs from t h a t species b y the head being narrower and demarcated from the b o d y, b y the posteriorly swollen (esophagus and also b y the tail, which is o f quite a different shape t h a n in the alternative species. I t is exceedingly elongated as in M. vulgaris b u t with a knee-like bend, narrower, whip-like and posteriorly pointed. The distance vulva -anus is much smaller than the length o f the tail and, in the t w o measured specimens, is 115 a n d 95/z.