: 1. (Annelida
: Oligochaeta) In aquatic
forms, the line formed by the nuclei of the fibers of the circular muscles.
2. (Arthropoda: Insecta) In eruciform Trichoptera, finely haired, longitudinal cuticular fold on each side of the abdomen. See also supraspiracular line.
3. (NEMATA) In some nematodes, lateral, longitudinal cuticular incisures beneath which the lateral nuclei of the hypodermis are found; lateral field lines. See also lateral ridge.