Flagellata and Primitive Alga. 185 
the cell is tetrahedral, with two pointed processes at each angle ; 
in Stylodinium (Fig. 10, 8, 9) the oval or spherical cell is attached 
to a substratum by means of a gelatinous stalk ; while in Glceodinium 
Fig. 10. Phytodiniack^e (1 to 13), Cystoflagellata (14 to 16), and 
Si LI COFLAG ELLATA (17 to 21). 
1, 2, Phytodinium simplex Klebs : in 1 the cell has divided, in 2 the nucleus 
is shown. 3 to 7, Tetradinium javanicum Klebs : 3, cell showing vacuolate 
cytoplasm, nucleus, an oil-drop, and numerous peripheral chromatophores ; 
4, empty cell, showing all four angles ; 5, cell attached to a root-hair of Azolla ; 
6, division ; 7, escape of the two daughter-cells from ruptured cyst-wall. 8, 
9, Stylodinium globosum Klebs : 8, stalked cell attached to a root-hair of Azolla ; 
9, escape of undivided contents by rupture of old cell-wall. 10 to 13, 
Glceodinium montanum Klebs : 10, cell with several gelatinous envelopes derived 
from older membranes; 11, division of the nucleus; 12, cell division; 13, 
older colony surrounded by gelatinous envelopes. 14, Noctiluca miliaris Suriray : 
side view (^optical section), showing on the left the short flagellum inserted in 
the “ pharynx,” at the base of the thick tentacle. 15, 16, Leptodiscus Hertwig : 
15, surface view, ventral side, showing on the right a wide depression with 
striated walls and on the left the narrow tube containing the flagellum; 16, 
side view (optical section). 17 to 19, Distephanus speculum Stohr: 17, cell 
showing skeleton and cell-contents (nucleus, cytoplasm, chromatophores) ; 
18, 19, two views of skeleton. 20, Monaster rete Schiitt: side view, showing 
the two flagella arising from equatorial groove, and the internal skeleton. 
21, Ampliitolus elegans Schiitt : side view, showing the elaborate skeleton. 
1 to 13, from Klebs; 14 to 19, from Deluge; 20, 21, from Schiitt, 
