PLATE LXXXVII. 



Figures magnified 500 diameters. 



Fig. 1. COSCINODISCUS BOREALIS, Bail.; Sill. J., July, 1856, p. 3; Schm. 



At., 63, f. 11. 

 " 2. CRASSUS, Bail.; Sill, J., 1856, p. 4; Schin. At., 61, f. 



19. 



" 3. DIORAMA, Schm. At., 64, f. 2, = C. gigas, Ehrb. 



" 4. ASTEROMPHALUS, Ehrb. ; with large cells. St. 



Monica. Schm. At., 63, f. 12. 



" 5. ROBUSTUS, Grev. ; St. Monica. Schm. At., 62, f. 6. 



" 6. CENTRALIS, Ehrb.; Cal. Schm. At.,63, f. 1; 60, f. 12. 



" 7. SUSPECTUS, Janiscb. Cal. Schm. At., 59, f. 2. The 



meshes only slightly smaller at margin than in 



center. 



" 8. OMPHALANTHUS, Ehrb. Margin arched. Mon- 



terey. Schm. At., 63, f. 2. 

 " 9. PERFORATUS, Ehrb. ; Richmond, Va. Series of 



puncta radiating; Schm. At., 64, f. 12. 



" 10. LINEATUS, Ehrb.; Schm. At., 59, f. 26. 



" 11. ROBUSTUS, Grev.; St. Monica. Smaller form of 



Fig. 5. Schm. At., 62, f. 5. 



