PLATE LXXXII. 



Figures magnified 500 diameters. 



Fig. 1. AULACODISCUS MARGARITACEUS, Rail's.; Prit., p. 844 ; Schm. At., 



37, f. 1-8. Cellules somewhat angular, too 



round in figure. 

 " 2. " MARGARITACEUS, smaller form, Cal. Schrn. At., 



37, f. 1-8. Rim too broad in figure. 

 " 3. " PETERSII, Ehrb. ; Schm. At., 35, f. 1-t; 41, f. 1, 2. 



Side view. Processes really in the center of 



the elevated bosses. 

 " 4. SPARSUS, Grev., T. M. S., 1866, p. 123, 11, f. 6; 



Schm. At., 36, f. 12. Cal. 

 " 5. KITTONII, Am.; Prit., p. 844, 8, f. 24; Schm. At., 



36, f. 5-7; 41, f. 6; M. J., 1860, p. 95, 6, f. 13. 



Areolation like Coscinodiscus, more or less 



hexagonal. 

 Figs. 6, 7. . PETERSII, Ehrb.; Figs. 3, 6, 7, are varieties of the 



same species. 



