PLATE LXXIV. 



Figures magnified 5IX) diameter^. 



Fig. 1. CosciNODisci's CRASSUS, (Craspedodiscus) Bail. ; Sill. J., 1856, 



p. 4: Schin. At,, 61, f. 19. Virginia. 



Figs. 2, 4. SOL, Wallieh. ; T. M. C., 1860, p. 38, 2, f. 12; 



Schin. At., 58, f. 41, 42, 46, 47 ; V. H., 129, f. 6. 

 Inserted under the impression the diatoms 

 were found in the fossil deposits of Virginia. 

 Are properly East India forms. 

 Fig. 3. ( 'RASPEDOPISCUS MICRODISCUS, Ehrb. Mik., 33, 17, f. 4; Prit.. 



p. 832. 

 " 5. ISOPORUS, (Coscinodiseus), Ehrb. Mik. ,33, 17, 



f. 3. Virginia. 

 Figs. (i. 7. CoseiNODisrus PATINA. Kg., K. B., 1, f. 15; Sill. J., 1841, 2, f. 



13, var. 



Fig. 8. ACTINOPTYCHUS MiNi'TTTs. (irev., T. M. S., 1866, p. 5, 1, f. 12. 



Figs. 9, Hi. MET,OSIRA BAILEYI, (Cestodisrnsi Am. <^. J. M., ls7s. p. 19, 3 ? 



f. 9. 



Fig. 11. ACTINOPTYCHUS GrRUENDLERi, Schin. At., 100, f. 4. St. Monica. 

 " 12. " UNDULATUS, var. Cronulatus; Schm. At., 1, 



f. 1-4, 109, f. 1; M. D., 19, f. 7; V. II., 22 his 

 f. 14. Maryland. 



" 13. ( 'osciNdDiscrs INTERMEDIUS, Ehrh. Mik., 33, 13, 3'. 

 " 14. ACTINOPTYCHUS ELEGANS. 



15. PERISTEPHANIA BAIT.EYI, Ehrb. At)h., 1870, p. 57, 3, 1, f. 13. 



Likely only a plate of Stephanodiscus 

 Niagarae. 



" 16. XANTHIOPYXIS UMBONATUS, Grev., T. M. S., 1866, p. 2, 1, f. 5. 

 17. Discus PORCELAINEOUS, Stodder. Stodder constituted this 



genus and species. He never figured it ; 

 mine is a figure from his description. A. 

 J. M., 1879, f. 14. 

 " 18. PERISTEPHANIA EUTYCHA, Ehrb. Mik., 35B, 4, f. 14. Cal. 



