Detailed descriptions and illustrations are presented of the nauplii (the only, or the first nauplius stage) of Bomolochus cuneatus, Holobomolochus spinulus, Chondracanthus gracilis, Ergasilus turgidus, Eudactylina similis, Pseudocharopinus dentatus, and Haemobaphes diceraus, and the copepodid stages of H. diceraus, P. dentatus, and Nectobrachia indivisa.The naupliar morphology of Ergasilus is similar to that of free-living Cyclopidae but differs in significant details from that of supposedly related Bomolochus. The nauplii of poecilostome and siphonostome copepods are similar. The morphology of the free-living larval stages might offer valuable clues to intrafamilial relationships of Lemaeopodidae. Differences were observed between copepodids of two species of Haemobaphes.