Lamarck included the Thysanura and the Myriapoda in his class Arachnida.
Ray's "Insects" comprised the Arachnids, Crustacea, Myriapoda and Annelida, in addition to the Hexapods.
the Myriapoda and some of the arthrostracous Crustacea.
In other words, the Malpighian tubes of the terrestrial Arachnida are homoplastic with those of Hexapoda and Myriapoda, and not homogenetic with them.
Newport, George, " Nervous and Circulatory Systems in Myriapoda and Macrourous Arachnids," Phil.