PLATE 18.— Foraminifera, etc. 



re 



Figu 



1. Rotalia Beccarii, shell of, from sea-sand. 



2. Rotalia Beccarii, shell of, dorsal view. 



3. Rotalia Beccarii, shell of, antero-lateral view. The oblique dark line indicates the part 



at which the anterior portion of the body protrudes, 



4. Rotalia Beccarii, shell of, ventral surface. 



5. Rotalia Beccarii, body freed from the shell. 



6. Rotalia Beccarii, portion of shell. 



7. Marginulina raphanus, shells, nat. size. 



8. Marginulina raphanus, body freed from the shell. 



9. Marginulina raphanus, shell, magnified. 



10. Marginulina raphanus, shell, longitudinal section. 



11. Orbiculina numismatis, shells, nat. size, from sea-sand. 



12. Orbiculina numismatis, shell, side view. 



13. Orbiculina numismatis, shell, front view, showing the apertm'es. 



14. Orbiculina numismatis, portion of shell, with the foramina, and the numerous orifices 



corresponding to the individual animals (Ehr.). 



15. Orbiculina numismatis; portion of anterior margin, with the oval holes for the 



protrusion of the expansions, and the transverse neck -like prolongations of the 



anterior part of the body. 

 Sorites orbiculus, shells, nat. size, side- and edge-views. 

 Sorites orbiculus, shell, side view ; two of the cells are broken open, others are shown 



partly closed by dendritic calcareous particles. 

 Sorites orbiculus, shell, side view ; from one cell protrude eight expansions. 

 Geoponus stella borealis, with the ex])ansions issuing from the foramina. 

 Geoponus stella borealis, after removal of shell by acid. 

 Rotalia perforata, living, side view. 

 Opercularia arabica, shell, side view, nat. size. 

 Opercularia arabica, shell, sm'face view, a, small, b, large papillae. 

 Opercularia arabica, spicuia. 

 Opercularia arabica, vertical section of shell over the chambers, a, large, b, small 



papillae ; c, lines of growth ; d, vertical tubes. 

 Opercularia arabica ; vertical section of septum, showing, — a, intraseptal vessel ; 



b, septum; c, grand channel of intercameral communication; d, part of spicular 

 cord. 



Opercularia arabica ; horizontal section of three large chambers, showing — a, cham- 

 bers ; b, septa ; c, intraseptal vessels ; d, branches to surfaces of septa ; e, branches 

 to wall of shell, &c.] /, marginal plexus ; g, terminal branches on the surface ; h, spi- 

 cular cord; i, half-formed septum. 



Opercularia arabica, perpendicular section, a, spicular cord; 'b, papillary tubes; 



c, truncated vessels of marginal plexus ; d, small channels of intercameral commu- 

 nication ; e, grand channel of the same ; /, septum. 



Numtnulites acuta, vertical section, a, spicular cord; b, truncated vessels of marginal 

 plexus ; c, chambers of central plane ; d, vertical intraseptal vessels ; e, horizontal 

 intraseptal vessels ; f, chambers on each side of central plane ; g, vertical tubes. 



Eunotia tetraodon. a, side view; b, front view. 



Cymbella Ehrenbergii. a, side view ; b, front view. 



Coscinodiscus radiatus. a, side view; b, front view. 



Rotalia ijerforata, from chalk, b, fragment. 



16. 



17. 



18. 

 19. 

 20. 

 21. 

 22. 

 23. 

 24. 

 25. 



26. 



27. 



28. 



29, 



30. 

 31. 

 32. 

 33. 

 34. 

 36. 

 38, 

 40. 

 42, 

 43, 

 44, 

 45, 

 46, 



Textularia striata. 

 Rosalina laevigata, basal view. 

 Rotalia turgida, side view. 

 Rotalia globulosa ; b, fragment. 



Lithocampe ?, fragment. 



Actinocyclus undulatus. a, side view 

 Campylodiscus ctypeus, side view. 

 Actinoptychus senarius. a, side view 

 Dictyocha gracilis, a, oblique view ; 



35. Textularia globulosa. 



37. Rosalina Icevigata, side view. 



39. Textularia aspera, fragment. 



4 1 . Rotalia globulosa, chambers filled mth air. 



b, front view. 



b, front view. 

 », side view ; c, front view. 



