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



PLATE 42. 



FIG. 1. SPIROLOCULINA ROBUSTA BRADY. SEE PAGE 296. 



a. Horizontal Section. b. Transverse Section. 



FIG. 2. SPIROLOCULINA ROBUSTA BRADY. (TRANSITION STAGES FROM BILOCULINA COMPRESSA.) 



SEE PAGE 296. 



FIG. 3. SPIROLOCULINA LIMBATA D'ORBIGNY. SEE PAGE 296. 

 FIG. 4. SPIROLOCULINA PLANULATA LAMARCK. SEE PAGE 297. 



