Vol. 3] Kofoid. — Dinoflagellata — New Species. 305 



longissimum (Schroder), and from the form figured by Schiitt 

 ('93, fig. 21, Va) in its postindentation, median position of the 

 apical on the epitheca, in its much smaller size, more sinuous 

 horns and delicate habit. Karsten's ( :06) C. tripos flagellifera 

 forma angusta includes (his figure 33a) C. inflexum Gourret 

 and this species (his fig. 33&) which differs from C. inflexmn in 

 its narrower shoulders, less localized major flexures, and greater 

 postobiiquity. 



Length, 260-430/* ; transdiameter, 35-40/a. 



Eare in plankton of tropical character at San Diego. 



Ceratium ostenfeldi, sp. nov. 



f'l. 26, figs. 22-25. 



Ceratium volans, Ostenfeld og Sebmidt( :01), p. 168, fig. 21. This 

 is not C. (tripos var. ?) volans Cleve (:00), p. 15, pi. 7, fig. 4. 

 Cleve's species is C. carriense Gourret. 



Ceratium (tripos var.) vultur, Okamura and Nishikawa (:04), pp. 

 123-124, pi. 6, fig. 8. Also as C. (tripos var.) vulture. 



Ceratium volans Cleve forma, Schroder (:06), p. 363, fig. 34. 



A very large species of the macroceros group, of robust habit, 

 long, spreading, straightish, symmetrical antapicals with open 

 tips. Deep postindentation. Antapical angle 85°-90°. Antap- 

 icals not so spreading as in C. carriense, and more so than in C. 

 macroceros. 



Length, 530-740/x; apical horn, 390-665/i,; antapicals, 435- 

 675|U,; distance between arms at girdle, 300-380/*; at tips, 675- 

 920/t. 



Eupelagic in warm temperate seas. 



In material examined by me this species is distinct from both 

 C. carriense Gourret and C. macroceros (Ehrbg). 



Ceratium reticulatum spirale, subsp. nov. 



PI. 27, figs. 27, 28. 



Differs from C. reticnlatuin Pouchet ('83) [^ C. hexacan- 

 thum Gourret and C. tripos var. iuaequale Gourret ('83); not 

 C. reticulatum Imhof ( '83)] in the fact that the left antapical is 

 not only carried across the apical on its ventral (occasionally 

 dorsal) side but is coiled up in a nearly flat spiral of 1-4 turns. 



