PLATE CVIII. 

 Figures magnified 500 diameters. 



Fig. 1. TRICEKATIUM PILEOTAJS, Elirb. Mik., 35a, 21, f. 17. 



"' *2. " PII.EUS, Ehrb. Mik., 19, f. 18. 



3. OBTUSUM, Bright, M. J., 1853, p. 251, 4. f. 20. 



Virginia. 



4. AMPHITETRAS ORNATA, Grev.; =Tric. pentacrinum, Wallach, 



M. J., 1858, 12, f. 10-12; T. M. S., 1861, p. 45; 

 Sclim. At., 98, f. 18. 

 Figs. 5, 6. CYMATOPL.EURA ELLIPTICA, S. B. D,, 10, f. 80. Normal and 



twisted form, or forma spiralis. 



Kig. 7. COSCINODISCUS CALIFORNICA. Do not recognize this. 



" 8. AULISCUS MUTABILIS, Grev. Monterey. T. M. S., 1863, p. 44. 



PI. 2, f. 11. 

 " 9. ACTINOPTYCHUS BISEPTINARIUM, Ehrb. Mik., 33, 16, f. 5. One 



of the forms of A. Ehrenbergii. 

 10. QUINARIUS, Ehrb., K. B., 1, f. 20; Mik., 33, f. 



16. 

 Figs. 11, 12. COSCINODISCUS PUNCTATUS, Ehrb. Mik., 18, f. 40, 41; Sm. Sp. 



T., No. 97. 



" 13-15. SURIRELLA CAMPYLODISCUS, K. B., 28, f. 26 ; Rab., 3, f. 4. The 



same as Campyiodiscus spiralis, which is 

 also better proportioned. See Plate. 



Fig. 16. TRIOERATIUM RETICUIATM, Schrn. At, 76, f. 26. Compare PI. 



104, f. 5, 6. 



