FIGURES 10 - 12 



Fig. 10. A, B, E-G. Ceratium subrobustum (Jorg.) Nielsen. A, long-horned form 

 with curved apical horn, from south of Easter Island, station 53; B, long-horned form from 

 central Pacific, station 99; E, short-horned form from central North Atlantic, station 19; 

 F, short-horned form from central Pacific, station 158; G, chain from central Pacific, sta- 

 tion 97. 



H, K-N. Ceratium pentagonum subsp. tenerum (Jorg.). H, short-horned form from 

 the tropical Atlantic, station 24; K, long-horned form from the tropical North Atlantic, sta- 

 tion 19; L, small form from southeastern Pacific, station 79; M, chain from Humboldt Cur- 

 rent, station 73; N, long-horned form with curved antapical horns from off California, station 

 133. 



C, D, I, J. Ceratium pentagonum subsp. pacificum n. subsp. C, comparatively thin- 

 walled individual from station 118; D, heavy-walled, short-horned form from station 123; I, 

 large, long-horned form from station 122; J, thin-walled form from same sample as C. 



Fig. 11. A, Ceratium setaceum Jorgensen, from station 110, north of Guam. 



B-D. Ceratium teres Kofoid. B, from station 101, northeast of Marshall Islands; C, 

 from station 141, north of Hawaii; D, two-celled chain from station 85, Tuamotu Islands. 



E-G. Ceratium lineatum (Ehr.) Cleve. E, from station 6, off Ireland; F, specimen 

 similar to C. minutum from station 10, southeast of Greenland; G, from station 11a south- 

 east of Greenland. 



H, Ceratium kofoidii Jorgensen from station 111, southeast of Japan. 



J, Ceratium peniculatum (Lemm.) Cleve. Partly separated. Specimen from station 45, 

 southeast Pacific. 



I, K-N. Ceratium bigelowii Kofoid. I, enlarged ventral view of specimen shown in M, 

 from station 47, southeast Pacific; K, specimen with little expanded body from station 154, 

 central Pacific; L, latero -ventral view of specimen from station 158, central Pacific; M, 

 dorsal view of specimen shown in I; N, right lateral view of same. 



O-S. Ceratium inflatum (Kofoid) Jorgensen. O, dorsal view of specimen from station 

 101, northeast of Marshall Islands; P, ventral view of specimen from station 20a, tropical 

 Atlantic; Q, dorsal view of specimen from station 99, north of Phoenix Islands; R, right 

 lateral view of specimen from station 101, northeast of Marshall Islands; S, ventral view of 

 specimen from station 54, near Easter Island. 



T-V. Ceratium longiro strum Gourret. T, from station 145, central North Pacific; 

 U, from station 98, north of Phoenix Islands; V, from station 103, north of Marshall Islands. 



W-AA. Ceratium falcatum (Kofoid) Jorgensen showing variation in size and curvature. 

 W, from station 52, south of Easter Island; X, from station 158, northeast of Samoa; Y, from 

 station 108, north of Guam; Z, from station 50, west of Easter Island; AA, from station 76, 

 southeast Pacific. 



BB-DD. Ceratium extensum (Gourret) Cleve. BB, specimen with well-developed 

 right antapical horn, ( C. strictum) from station 81, tropical Pacific; CC, typical specimen 

 without right antapical horn, from station 158, tropical Pacific; DD, enlargement of same 

 specimen; EE, Ceratium fusus (Ehr.) Duj. Wide form from cold North Pacific region, sta- 

 tion 123. 



Fig. 12. Ceratium b6hmii n. sp. A, from station 114, off Japan; B, from station 98, 

 north of Phoenix Islands; C, from station 40, off Ecuador. 



168 



