ABSTRACT
Halicyclops aberrans sp. n. from two localities of the River Capim, Pará State, Brazil, is described and figured. It differs from all previously described species of the genus in possessing the inner apical spine of the third endopodal segment of swimming legs 3 and 4 reduced and turned upwards, and by the spinal formula of the third exopodal segment of the swimming legs (2.3.3.2).