THE VENTRICULID.E 



THE CHALK: 



THEIR MICROSCOPIC STRUCTURE, AFFINITIES, 

 AND CLASSIFICATION; 



INCLUDING 



FIGURES AND DESCRIPTIONS OF EVERY SPECIES. 



'BY 



OULMIN SMITH 



LONDON: 

 PRINTED BY RICHARD AND JOHN E. TAYLOR, 



RED LION COURT, FLEET STREET. 



1848. 



