1034 CLEVE, P. T., PLANKTON FROM THE RED SEA. 



Nitzschia (pungens var.) atlantica Cl. — 27 N. 34° E. — 



(Pseudoeunotia dolioliis Wallich. Not found in the Red 

 Sea but in the Gulf of Aden, where it occurred abundantly at 

 11° N. 51° E. This species is very characteristic for the southern 

 Indian Ocean and southern Atlantic.) 



RMzosolenia alata Btw. — • 16° — 27' N. 41° — 34' E. {temp. 

 25,5; sal. 38,8). — Arabian Sea, temperate Atlantic. 



var. gracillima Cl. — ■ Together with the coarser typical form. 



R. robusta Norm. — 19° N. 39° E. {temp. 25,5; sal. 38,8). 

 — Arabian Sea, Malay Archipelago, along the coasts of the 

 tropica! Atlantic. 



R. Shrubsolei Cl. — 27° N. 34° E. — Temperate Atlantic. 



R. styliformis Btw. — 22° N. 37° E. {temp. 23,65; saL 

 39,5). — Arabian Sea, Malay Archipelago, southern Indian Ocean, 

 southern and temperate Atlantic. 



Striatella delicatula (KüTZ.), very abundant at 13° — 19° N. 

 43°— 39° E. {temp. 24,8 to 25,5; sal. 36,35 to 38,8). — Arabian 

 Sea, Indian Ocean. 



Thalassiosira rnonile n. sp., very common at 19° N. 39° E. 

 {temp. 25,5; sal. 38,8). 



The cellules occur inbedded in globular gelatinous masses, 

 united into raoniliform colonies. The pervalvar axis shorter than 

 the diameter of the valve. The alveoli of the valve have the 

 same arrangement as in Coscinodiscus excentricus, about 12 in 

 0,01 mm., somewhat closer near the margin, which is provided 

 with a row of small tubercules, 3,5 in 0,01 m.m. Between the 

 central alveoli there is a small porus. The cylindrical part of 

 the valve as well as the zone is very finely striate (29 strife 

 in 0,01 m. m.). 



l'ig. 2. Thalassiosira rnonile, Fig. 3. A cellule in the 



a ehain 250 t. m. zonal view, 1,000 t. ni. 



