poecilopoda

from The Century Dictionary.

• In Latreille's system of classification, the second order of his Entomostraca, divided into two families, Xiphosura and Siphonosloma.

from the GNU version of the Collaborative International Dictionary of English.

• noun plural Originally, an artificial group including many parasitic Entomostraca, together with the horseshoe crabs (Limuloidea).
• noun plural By some recent writers applied to the Merostomata.