Some new species of Benthimermis Petter, 1980 (Benthimermithidae, Nematoda) from the South Indian Ocean.Six new species of Benthimermis collected from the shallows of the Crozet-Prince Edward ridge (South Indian Ocean) are described. Benthimermis australis n.sp. is the first species in the genus of which both male and female are known; the male differs from previously described males in lacking cervical alae as well as a cuticular ring-like thickening around the amphids; the female is characterized by a rounded tail with a thick mucron and with a cuticular thickening at its end. Benthimermis crozetensis n.sp., of which only the male is known, resembles B. breviptera in the form of the cervical alae and reproductive system, but is distinguished by the length of the cervical alae and tail, and the diameter of the anterior vas deferens. The following four species are known only by their females: B. hureaui n.sp. is distinguished by a short conical tail; B. edouardensis n.sp. is distinguished by a tail with a long terminal spike bearing refringment granules; B. marionensis n.sp. and B. arnaudi n.sp. are characterized by a short round tail without a cuticular thickening at its end and are distinguished from one another by the length of the ovaries.These species are the first in the Benthimermithidae which have been found in relatively shallow sediments (between 90 and 980 m).Keys to males and females of the genus Benthimermis are given. ac]19820408.