hippocrepian

from The Century Dictionary.

• Like or likened to a horseshoe in shape; hippocrepiform: specifically applied to certain ectoproctous Polyzoa which usually have the lophophore prolonged into two lobes so as to be horseshoe-shaped, as well as to such a lophophore itself.
• noun A polyzoan having these characteristics. See Phylactolæmata.

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

• noun (Zoöl.) One of an order of fresh-water Bryozoa, in which the tentacles are on a lophophore, shaped like a horseshoe. See phylactolæma.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun One of an order of freshwater bryozoa, in which the tentacles are on a lophophore, shaped like a horseshoe.