186 
Protozoa in Tipula 
group of chromatin granules (Figs. 18 and 19 a). As a rule it is possible 
to make out one flagellum arising from a granule on the anterior border 
of the cytostome. Very^ rarely the nucleus is of vesicular form, with a 
definite nuclear membrane and a central group of chromatin grains 
(Fig. 190. 
The cysts (Fig. 20), now found for the first time, are minute oval 
bodies (.3'5 y, x 3 fj, to 4 yu, x 3 p-), enclosed by a double membrane, and 
containing a gi’oup of chromatin granules near the apex and a dark 
hook-shaped line in the position of the cytostome border. 
Fig. 20. Cyst of Embadomonas agilis. 
Fig. 21 a. Embadomonas alexeieffi. 
Fig. 21 b. Embadomonas alexeieffi. Slender individual. 
(h) Embadomonas alexeieffi, n. sp. This is a larger flagellate 
(12 p, X 8 p, is a common size, while large individuals measure as much 
as 16 p X 7 p), of clumsier form, and with a much thicker periplast 
(Figs. 21 a and b and 22). The cytostome is not quite so large in pro¬ 
portion as in the foregoing species, makes an angle with the long axis 
of the body, and has a very much more definite, deeply-staining border, 
often thrown into folds. The nucleus is almost always vesicular, with 
a definite membrane, and a central group of chromatin granules on 
a faint netwoi’k. A deeply-staining rod-shaped or crescent-shaped mass 
lies against the nuclear membrane : in some cases it appears to be 
