chilostomellidæ

from The Century Dictionary.

• A family of perforate foraminifers, typified by the genus Chilostomella, with the test calcareous, finely perforate, and polythalamous; segments which follow one another from the same end of the long axis, or alternately at the two ends, or in cycles of three, more or less embracing; and an aperture in the form of a curved slit at the end or margin of the final segment.