FIGURES 43-46 



Fig. 43. Peridinium pallidum Ost. A, anteroventral view of apex; B, latero-poste- 

 roventral view of ventral area and adjacent regions; C, diagram of same; D, diagram of A. 

 Magnification: A, D, x 810; B, C, x 660. (For symbols, see fig. 42.) 



Fig. 44. Skeletal dissection of Ceratocorys horrida Stein. A, in ventral view; B, in 

 apical view. Symbols: al, a2, first and second anterior intercalary plate; ac, anterior 

 cingular list; ant, antapical plate; apl, ap2, first and second apical plate; as, anterior sulcal 

 plate; ep, ventral epithecal pore; gl, g2, g5, g6, first, second, fifth, and sixth girdle plates; 

 Is, left sulcal plate; pc, posterior cingular plate; pi, posterior intercalary plate; pi, apical 

 pore platelet; pol-po3, po6, first to third, and sixth postcingular plates; prl-pr5, first to 

 fifth precingular plates; ps, posterior sulcal plate; ra, right accessory sulcal plate; rs, 

 right sulcal plate; vb, ventral body list; vs, ventral spine. 



Fig. 45. Diagram of the dimensions used in the study of body proportions in 

 Ceratocorys . (See p. 36 for explanation.) 



Fig. 46. Graphical representation of the relationships of the species of Ceratocorys . 



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