3512. Body soft and slightly annulate, maxillæ, feet and branchiæ arrested; live by suction as parasites upon other animals, mostly fishes.
Fam. 1. Tritonia-like, Lernæaceæ.
Body soft, without shield, eyes and branchiæ; feet and maxillæ stunted; ova carried in two tubes at the hinder part of the body—Kiemenwürmer or Lerneæ.
Fam. 2. Patella-like, Argulaceæ.
Body distinguished into head, thorax, and abdomen, with few natatory feet, maxillæ moulded to form suctorial organs, mostly eyes; lay also strings of ova; head elongated in many in a scutiform manner. The so-called Fish-lice or Argulaceæ.
Fam. 3. Luftschneckenartige—Pycnogonidæ.
Body short, with four pairs of long feet; eyes, but no branchiæ and maxillæ; abdomen puny in size. The Whale-lice.
Order 4. Kammschneckenartige—Nagasseln.
3513. Body cylindrical, horny, and distinctly annulate, maxillæ, eyes, and mostly seven simple pairs of feet, branchiæ as cysts or leaves.
Fam. 4. Capulidenartige, Walzenasseln.