PLATE OX. 



Figures magnified 500 diameters. 



Fig. 1. COSCINODISCUS INCRETUS, A. S., Schm. At., 139, f. 1. Santa 



Monica. 



" 2. TKICERATIUM CAMPEACHIANUM. 



Figs. 3, 4. CAMPYLODISCUS BICOSTATA, W. S.; T. M. S., 1854, p. 75, 6, f. 4; 



V. H., 75^ f. 2; Schrn. At., 55, f. 4, 5. 

 Fig. r>. CYCLOTEL.LA COMPTA, var. Bodonica, Kg.; V. H., 92, f. 16-22; 



V. II., 93, f. 21, etc. Br. Columbia. 

 Figs. (i. 7. BIDDULPHIA ANCH-LATA, A. S.; Nottingham, Md. Schm. At., 



141, 7, 8. Valves are marked somewhat like 



Coseinodiscus, 



Fig. 8. HYALODISCITS RECTICULATUS, A. S., Schm. At., 140, f. 7. Mon- 



terey. 

 Figs. '., 10. BIDDTJLPHIA MEMBRANACEA, Cleve.; W. Ind. diatom ; 5. f. 33. 



Near Zygoceros Balaena of Ehrb. 



