1) Arthropod genus 2) Genus phthirius 3) Genus phthirus 4) Phthirius 1) Phthirius 
(thir´әs) a genus of lice. P. pu´bis is the pubic or crab louse, a species that infests human pubic hair and sometimes other hairy areas; see also pediculosis pubis.
Type: Term Pronunciation: thī′rŭs See: Pthirus
Phthirus 1. A genus of sucking lice belonging to the order Anoplura. 2. True lice or crab lice.