1. Characters of taxonomic value in the family Philometridae are discussed; the important structures taken into account are the cuticle, cephalic papillae, oesophagus and the tail of the parasite.
2. Two new species of Philometra are described and Ph. lateolabracis Yamguti, 1935 is redescribed from new fishes of the Arabian Sea.
3. Two new subgenera have been made under the genus Philometra and named as Ranjhinema and Alinetna.
4. Philomeiroides piedropliies (Johnston and Mawson, 1940) and Ph. anguillac (Ishii, 1916) are redescribed.
5. Buckleyella and Thwaitia are described as new genera, the diagnosis being based on the structure of the cuticle, cephalic papillae and the tail.
6. A key to the genera of Philometridae is provided with the diagnosis of each genus and subgenus. Some of the species formerly described under Philometra are provisionally transferred to other genera of this family.