philodinidæ

from The Century Dictionary.

• A family of rotifers, of the order Bdelloida, having the corona a pair of circular lobes placed transversely, and the velum a continuous marginal curve bent on itself at the dorsal surface so as to encircle the corona twice, the mouth being between its upper and lower curves. It contains the genera Philodina, Rotifer, Actinurus, and Callidina.