In view of the dissimilar tails found in the two sexes of Sicaguttur sartum Siddiqi, 1971 from West Bengal, males being reported for the first time, diagnosis of the genus Sicaguttur Siddiqi, 1971 is emended. A new species, Sicaguttur longicaudatum, is described from Azamgarh, India. Jairajpuria shamimi n. gen., n. sp. is proposed from West Bengal. Jairajpuria n.gen. differs from Thornenema in having an off-set and cap-like lip region, longer uterine sac, and S2N more anteriorly situated from S2O. Mehdinema prabhae n. gen.,1), n.sp. is proposed for S. sartum apud Ali & Prabha, 1974. Mehdinema n. gen. differs from Sicaguttur mainly in having similar tails in both sexes. Mehdinema indicum (Ali & Prabha, 1974) n.comb. is proposed for Sicaguttur indicum. Mehdinema coomansi n.sp. is also described from West Bengal and is compared with M. prabhae and M. indicum. After comparing the paratype females of Thornenema wickeni Yeates, 1970 with the Indian specimens having similar tails in the sexes which were identified as T. wickeni by Ali & Prabha (1974) and for which they proposed a new genus Indodorylaimus, we conclude that Ali & Prabha misidentified the Indian specimens and T. wickeni is well placed under Thornenema. The diagnosis of the family Thornenematidae is emended. The genera Thornenema, Sicaguttur and Jairajpuria n.gen. are grouped in the subfamily Thornenematinae and the subfamily Sicagutturinae Ali & Prabha, 1974 is not recognized. A new subfamily Mehdinematinae1) is proposed under Thornenematidae for the reception of Mehdinema n.gen., Willinema Baqri & Jairajpuri, 1967, Indodorylaimus and Timminema Khan, 1977. A key to the genera of the family Thornenematidae is provided.