Report of U. S. National Museum 1897. Flint. 



PLATE 64. 



FlG. 1. CRISTELLARIA GIBBA D'ORBIQNY. SEE PAGE 317. 



FiQ. 2. CRISTELLARIA ARTICULATA REUSS. SEE PAGE 317. 



FlG. 3. CRISTELLARIA ORBICULARIS D'ORBIGNY. SEE PAGE 317. 



FIG. 4. CRISTELLARIA ROTULATA LAMARCK. SEE PAGE 317. 



a. Horizontal Section. 



