Definitions are given of the family Podacaridae and the three genera, Podacarus, Alaskozetes and Halozetes, presently included within it. Observations on several collections from the Antarctic and sub-Antarctic regions are discussed in an attempt to determine various morphological trends which may serve as useful indicator,; of generic and specifie differences within the family. The three genera are separated on the basis of well defined differences, and parallel trends in the development of ventral neotrichy, regression of the sensillus and pseudostigmata and regression of interlamellar setae are discussed. A key to the genera and species within the family is given.