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



PLATE 51 



FIG. 1. ORBITOLITES MARGINALIS LAMARCK. (BY TRANSMITTED LIGHT.) SEE PAGE 304. 



a. Section, 



FIG. 2. ORBITOLITES DUPLEX CARPENTER. SEE PAGE 305. 



, f>. Sections. 



FIG. 3. ORBITOLITES DUPLEX CARPENTER. (BY TRANSMITTED LIGHT.) 



