P. T. CLBVE, PLANKTON COLLECTED BY MR. THORILD WULFF. 335 



Plankton-forms noted.* 



Myxophyceae. 



Heliotrichum radians Wille (Trichodesmiuwi thiebaulti Clev.). 

 Bed Sea: X, 14°— 13° N. 43° E. 

 Gulf of Aden: X, 12° N. 45" E. 

 T. 29,3 to 30,5 — S. 36,76 to 37,70 — Spis. 3. 



Chlorophyceae. 



Halosphaera viridis Schmitz. 



AU. IX, 48° N. 6° W. — II, 37° -47 =N. 7 — 10° W. 

 Medit. X, 37° N. 2° W. to 34 X. 24° E. — I, 33° N. 30° E. 



to 36° X. 4° W. 

 Bed Sea: X, 30°— 23 X. 33—37° E. 

 Arab. Sea: I, 21 X. 62° E. 

 T. 19,6 max. 29,2, min. 11,5 — S. 37,89, max. 42,81 min. 



35,50 — Spis. 24. 



Cystae. 



Pyrocystis hamuliis Clev. 



Bed Sea: I, 15° X. 41 E. — T. 24,8 — S. 37,63 — Spl. 1. 

 P. pseudonoctiluca J. Murray. 



Meäit. X, 35—32 X. 18°— 30° E. — I, 35° X. 19" E. 



Bed Sea: X, 27°— 20° X. 35°— 39° E. — I. 15°- 20° X. 

 41°-39° E. 



Gulf of Aden: I, 12° X. 44° E. 



T. 26,3, max. 30,7, min. 15,8 — S. 39,02, max. 40,57, min. 

 36,24 — Spis. 17. 

 Xanthidinm paucispiiiosum Clev. 



Medit. X, 38°-32° X. 8°— 32° E. 



Bed Sea: X, 30°— 23° X. 33°-37° E. 



Gulf of Aden: X, 13° X. 49° E. 



* In the following T denotes the temperature in C° of the water. in which 

 a form has been found, nsually as means of several observations, S the salinity 

 in p. m.. Sple and Spis denote the number of samples, in which a form has 

 been found. Chsetognata. Amphipoda. Thaliacea, Pteropoda and Proehordata 

 ha ve not been examined. 



