xiphosura

from The Century Dictionary.

• noun Same as Xiphisura: in this form, in Lankester's classification, brought under Arachnida as one of three orders (the other two being Eurypterina and Trilobitæ) brigaded under the name Delobranchia.

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

• noun plural See xiphura.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun horseshoe crabs and extinct forms