SUMMARY A new genus Opisthodorylaimus closely related to Thornenema Andrassy, 1959 and Mesodorylaimus Andrhssy,

1959 is proposed, along with the description of three new species, viz., O. maqsoodi n. sp. (type), O. caudatus n. sp., ’ and O. chamoliensis n. sp. It differs from Thornenema in having an unsclerotized lip region and a broad odontostyle, while from Mesodorylaimus i t differs in having an opisthomonodelphic reproductive system as well as a broad odontostyle. Jairajpuria oryzae n. sp. differs from J. shamimi Baqri & Jana, 1980 in the shape of lip region, post-eriorly situated vulva, unsclerotized vagina and in the absence of a sphincter at the oviduct-uterus junction. Dorylaimus siddiqii n. sp. is close to D. thornei AndrBssy, 1969, but differs in having a shorter and narrower body, differently shaped lip region, smaller and narrower odontostyle and in the abs nce of vulval papillae. Calodorylaimus indicus n. sp. differs from C. octo Andrassy, 1969 in having a smaller body, shorter odontostyle, longer oesophagus, posterior vulva and smaller spicules and tail. The male of Thornenema cavalcantii is redescribed. Laimydorus pseu-dostagnalis and Afrodorylaimus geniculatus are reported for thefirst time from India