302 University of CaUfonna Publications. [Zoology 



continues posteriorly for half the length of the hypotheca. The- 

 cal wall hyaline, structureless, Avithout suture lines in individuals 

 examined. 



Nucleus relatively large, ellipsoidal with moniliform chroma- 

 tin reticulum. A large spherical amyloid body is present and 

 there are numerous ellipsoidal peripherally located chromato- 

 phores of yellowish color. 



Differs from H. triquetra in its relatively greater trans- 

 diameter and consequently stouter form, and in the prominent 

 antapical spine. 



Length, including spine, 45/x ; transdiameter, SO^a. 



In surface oceanic plankton off San Diego in June. 



Ceratium calif orniense, sp. nov. 



PI. 23, figs. 6-9. 



Ceratium furca var. baltica (in part), Entz ( :05), pp. 99-101, Taf. 



1, Fig. 8. 

 Ceratium tripos macroceros (in i)art), Entz (:05), pp. 101-102, 



Taf 2, Figs. 13, 14. 



This is a small species of delicate habit with slender antapicals 

 curved regularly toward or even beyond the horizontal plane. 

 Midbody resembles that of the macroceros group. Tips of the 

 antapicals are closed, acute. The postmargin is wide and ab- 

 ruptly delimited from the bases of the antapicals. Thecal wall 

 hyaline, porulate, but otherwise structureless. 



Not in the form cycle of C. furca balticum {= C. lineatuni) 

 and C. tripos macroceros (= C macroceros) as suggested by 

 Entz (:05). 



Rare in oceanic plankton at San Diego. 



Ceratium gallicum, sp. nov. 



PI. 24, figs. 10-12. 



Ceratium tripos var. macroceros, Gonrret ('83), pp. 26-27, pi. 2, 



fig. 41. 

 Ceratium tripos var. macroceras (in part), Schroder (:00), p. 15, 



Taf. 1, Fig. 17 f. 

 Ceratium tripos macroceros (in part), Entz (:05), p. 100, Taf. 2, 



Figs. 15, 16. 

 Ceratium tripos macroceros (in part), Karsten (:06), Taf. 23, 



Fig. 29 e. 



