EXPLANATION OF PLATES 



PLATE 9 



Gonyaulax digitale (Pouchet) Kofoid 



Fig. 1. Ventral view of theca showing plates. Specimen from Lor- 

 ing, Alaska, September 15, 1905. X 1000. 



Eig. 2. Ventral view of heavy theca possibly approaching fission. 

 From 0-5 m., August, 1907, Faeroes Channel. X 1000. 



Fig. 3. Ventral view, showing surface markings, from same collec- 

 tion as specimen in figure 2. X 1000. 



Fig. 4. Ventral view of heavily finned type. Loring, Alaska, Septem- 

 ber 15, 1905. X 1000. 



Fig. 5. Ventral view of very rugose form with reticulations replac- 

 ing spines in antapical fins. Surface reticulations shown only on plates 

 6", IP, and 1"". From same collection as specimen shown in figure 2. 

 X 1000. 



ABBREVIATIONS 



1-6 — girdle plates. cl. pJ. — closing platelet. 



l'-3' — apical plate. f. — fin of ventral area. 



i"-6"— precingular plates. fl. po.— flagellar pore. 



l>"-6"' — postcingular plates. int. pi. — intermediate plates of ven- 



IP — posterior intercalary. tral area. 



1"" — antapical plate. post. 2>i.— posterior plate of ven- 



ant. pi. — anterior plate of ventral tral area. 



area. v. po. — ventral pore. 

 ant. sp. — antapical spine. 



Figures 1, 2, 4, 5, drawn by Mrs. Josephine Rigden Michener, figure 

 3 by Miss Ethel Abeel. 



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