Explanation of abbreviations in figures, text, and plates. 



l'-3', apicals. 



l a -2 a , anterior intercalaries. 



l"-6", precingulars. 



l'"-6'", postcingulars. 



1-6, girdle plates. 



1p posterior intercalary. 



l c , posterior intercalary plate. 



1"", antapical. 



?, anterior intercalary plate or apical 3' (?). 



ant. pi., anterior plate of ventral area. 



att. area, attachment area. 



int. pis., intermediate plates of same. 



n., nucleus. 



post, pi., posterior plate of same. 



v. a., ventral area. 



v.po., ventral pore. 



fl.po., flagellar pore. 



cl.po., closing platelet of apex. 



cyt., cytoplasm. 



/., fin. 



st. gr., starch granules. 



th., theca. 



