Category:Tetrapneumona

Tet`ra*pneu"mo*na, n. pl. Etym: [nl. See tetra-, and pneumo-.] (zoöl.)

Defn: a division of arachnida including those spiders which have four Lungs, or pulmonary sacs. It includes the bird spiders (mygale) and The trapdoor spiders. See mygale.