polar body

One of two small cells produced, each during one of the two meiotic cell divisions, which are then discarded in the creation of the haploid germ cell.

hook

A small lump on the gubernaculum of the male tail. This structure lies on the ventral surface just anterior and central to the base of the spicule openings and contains a sensory structure called the hook sensillum.

pharyngeal-intestinal valve

A group of six equivalent cells forms a tightly constructed 'valve' that links the posterior bulb of the pharynx to the anterior four cells of the intestine. These six cells comprise a small epithelial channel with a cuticular lining in continuity with the pharyngeal cuticle and link the lumen of the pharynx to the large lumen of the anterior intestine.

cuticular ala

Small linear ridges running along the lateral lines of the cuticle, lengthwise along the body; these thickenings lie in register with the seam cells which likely produce them and are present in the cuticle of the L1, dauer and adult stages, but not in other larval stages. The alae are suspected to provide better traction when the animal generates a bodywave. Since the animal usually lies on its side, the alae are in perfect position to catch against the substrate.