THE series of minute, adherent species of Brachiopoda brought together in the following discussion are usually assigned by American palæontologists to the genus Strophalosia, but recent writers have come to recognize the fact that, in America at least, the genus Strophalosia is a polyphyletic group. Dr. Stuart Weller, in his monograph on the Mississippian Brachiopoda (1914), all but recognizes the generic value of these minute shells when he points out the lack of harmony in the series of forms which he places in the genus Strophalosia.