924 



P. T. CLEVE, S. ATLANTIC PLANKTON. 



Silicoflagellatse. 



Dictyocha flbula Ehe. This species was foiind in almost all 

 samples frora 41° S. 6° W. to 44° S. 45° E.; at 43°— 42° S. 

 73°— 76° E. and at 32° S. 91° E. 



Distephanus speculum (Ehe.) StöhR. — More or less common 

 in all samples from 41° S. 6° W. to 44° S. 48 E. andat43°S. 

 73° E.; 34° S. 89° E. and 33 S. 90^ E. 



Chloropliyllaceae. 



Halosphaera viridis Schmitz, forma minor: from 37' S. 

 23° W. to 39° S. 17° W., always rare. 



Cystae. 



Diplocystis antarctica Cl. N. Sp. — By this narae I distinguish 

 a unicellular alga, which seems to characterize the styli-plankton 

 of the southern hemisphere. As I have seen only alcohol-preserved 



specimens, I am unable to give 

 a complete description, but the 

 form of the cellula is so characteris- 

 tic, that this organism may neverthe- 

 less be easily recognized. The cellula 

 is somewhat flattened, constricted in 

 the middle, and thus divided in two 

 parts, of which one has a short 

 conical process. It multiplies by 

 division. Length 0,05; breadth 0,07 



a.b. Ordinary cellula in different po- m.m. — -"^ '§• <?• 



c. d. Celkirin division. This problematic form was found 



2^^ *• ^- in many samples, from 36° S. 24° W. 



to 44° S. 4° E.; at 45 S. 29° E. and frora 43° S. 57° E. to 

 36° S. 89° E. 



Diiioflagellatae. 



Ceratium (tripos) arietiimm Cl. (K. Sv. Vet. Akad. Handl. 

 XXXIV. N. 1 p. 13 PI. VII f. 3. C. trip. arcuatum forma 



