PLATE 10 



Fig. 6. Dorsal view of theca of Gonyaulax polygramma Stein, show- 

 ing plates. San Diego, December 12, 1904. X 1000. 



Fig. 7. Ventral view of same. The specimen figured shows an un- 

 usual number of antapical spines. X 1000. 



Fig. 8. X'entral view of theca of Gonyaulax spinifera (Clap, et Lach.) 

 Diesing sensii stricta. San Pedro Harbor, May 31. 1901. 



Fig. 9. Dorsal view of another individual from same collection, 

 showing theca after recent fission. The newer moiety is smooth, the 

 older reticulate. X 1000. 



Fig. 10. Ventral view of same. X 1000. 



ABBREVIATIONS 



1-6 — girdle series of plates. cl. pi. — closing platelet of apical 



l'-3' — apical series. region. 



l"-6" — precingular series. f. I. — fission line. 



l"'-6"' — jiostcingular series. //. po. — flagellar pore. 



IP — posterior intercalary plate. int. pi. — intermediate plates of ven- 



1"" — antapical plate. tral area. 



ant. pi. — anterior plate of ventral pof<t. pi. — jjostcrior plate of same. 



area. v. po. — ventral pore. 

 ant. sp. — antapical spine. 



Figures 6-8 drawn by Mrs. Josephine Rigdeu Michener; figures 9 and 

 10 by C. A. Kofoid and Mr. R. W. Harvey. 



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