The Collaborative International Dictionary
Tetrapneumona
Tetrapneumona \Tet`rap*neu"mo*na\, n. pl. [NL. See Tetra-, and Pneumo-.] (Zo["o]l.) 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.