Quick Quiz: Nouns Score: Change category, Flip order Reset Incorrect! Try again. Noun: genus thrinax Your choice? type genus of Treponemataceae: anaerobic spirochetes with an undulating rigid body; parasitic in warm-blooded animals type genus of the family Triopidae: small crustaceans with a small third median eye   (Noun: genus triops) lined snakes small to medium-sized fan palms