A division of Arachnoidea, including the daddy longlegs or harvestman (
Phalangium) and many similar kinds. They have long, slender, many-jointed legs; usually a rounded, segmented abdomen; and chelate jaws. They breathe by tracheæ. Called also
Phalangides,
Phalangidea,
Phalangiida, and
Opilionea. [
1913 Webster]