Report of U. S. National Muteum. 1897.— Flint. 



Plate 51 



-^"iiiS?!; 



Fig. 1. ORBITOLITES MARGINALIS Lamarck. > by transmitted light. > See Page 304. 



ii. Section. 



Fig. 2. ORBITOLITES DUPLEX Carpenter. See page 305. 



a, t. Sections. 



Fig. 3. ORBITOLITES DUPLEX Carpenter, (by transmitted light. > 



