Arachnida
Arachnida ({not transcribed}) , noun, plural
[New Latin, from Greek {not transcribed} spider.]
(Zoology) One of the classes of Arthropoda. See Illustration in Appendix.
They have four pairs of legs, no antenna nor wings, a pair of mandibles, and one pair of maxilla or palpi. The head is usually consolidated with the thorax. The respiration is either by tranchea or by pulmonary sacs, or by both. The class includes three principal orders: Araneina, or spiders; Arthrogastra, including scorpions, etc.; and Acarina, or mites and ticks.