ctenidium

ctenidium (noun; plural ctenida; Greek diminutive kteis, comb): 1. (Arthropoda: Insecta) a. A series of stout, peg-like spines on the head (genal ctenidium) and first thoracic tergite (pronotal ctenidium) of many fleas. b. A row of comblike bristles on the hind tarsus of Psocoptera.

2. (Ctenophora/Mollusca) A respiratory gill-comb

See also: gill.