pseudo-heart

from The Century Dictionary.

• noun In brachiopods, one of several tubular infundibuliform organs by which the perivisceral cavity communicates with the pallial chamber, and which were described by Owen as hearts. See cut under Waldheimia.

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

• noun (Zoöl.) Any contractile vessel of invertebrates which is not of the nature of a real heart, especially one of those pertaining to the excretory system.