1. The frequency of infection, the attachment and the dependence of the parasite on the host as well as the respiratory and osmotic relations of the parasite with the surrounding medium are briefly noted.
2. The various divisions of the body and the appendages are described.
3. An account of the structure of the body wall, the gut, the vascular and nervous systems, and the reproductive organs is given.
4. Larvae belonging to the first and second chalimus stages are described and compared with the larvae of other lernaeids as regards suspension.