(Redrawn after Furman and Catts 1970)
The body is laterally flattened. The head has sucking mouthparts. Combs are sets of large, posteriorly-directed, spines that aid attachment, and one, both, or neither may be present in a given species. The legs are well-developed with small terminal claws. The only easily-seen part of the internal genitalia is the small spermatheca.