Trilobita and Eurypterida, among the Crustacea; making altogether five for the great sub-kingdom of Annulosa.    From Wordnik.com.  [Essays] Reference

This paper, with Hünicken as a coauthor, revises the identity of this fossil as a “bizarre eurypterid”, a water scorpion Eurypterida.    From Wordnik.com.  [Archive 2006-02-01] Reference

But a complete development, such as already obtains in the lobster, &c., was reached by the Eurypterida and Trilobites of the palæozoic strata; and annelids, probably formed mainly like those of the present day, abounded during the deposition of the oldest fossiliferous rocks.    From Wordnik.com.  [On the Genesis of Species] Reference

Amongst the molluscous animals we have members of the very highest known class, namely, the Cephalopods, or cuttle-fish class; and amongst articulated animals we find Trilobites and Eurypterida, which do not belong to any incipient worm-like group, but are distinctly differentiated.    From Wordnik.com.  [On the Genesis of Species] Reference

Eurypterida, among the Crustacea; making altogether five for the great sub-kingdom of Annulosa.    From Wordnik.com.  [Lectures and Essays] Reference

Eurypterida, 141, 171.    From Wordnik.com.  [On the Genesis of Species] Reference