THE PHYLOGENY OF THE GENUS BRACHIOMONAS gI 
tion about 1440 diameters; plate 4 done with Spencer 2 mm. oil immers. obj. 
and Leitz compens. oc. 6, magnification about 1300 diameters; both reduced 
in reproduction to about 720 diameters. 
PLATE 3 
Fics, 1-7. BRACHIOMONAS SUBMARINA Bohlin, type form 
Fic. 1. Vegetative cell; posterior horn filled with colorless cytoplasm. 
BiG oe romatophore filling the extremities: Dec. 191 
Fic. 3. Colorless cytoplasm in extremities; stigma and pyrenoid lying 
on the ee side of the cell: March, 1921. 
Fic. 4. Anterior polar view of similar cell; vacuoles in chromatophore. 
Fic. 5. Slender form similar to Bohlin’s f. 7b of B. gracilis (fixed with 
Oosmic wie vapor). 
IG. [oe slender form: showing typical position taken by 
living zoospore temporarily at rest, the pyrenoid and stigma lying in the 
center of the under side (osmic v. sie): April 1921. 
1G. 7. Anterior polar view of similar cell, showing cilia stretching out 
n plane ae to that in which the nucleus, pyrenoid, and stigma 
he pically lie 
Bes 8-27. BRACHIOMONAS SUBMARINA forma OBTUSA Hazen 
Fic. 8. Chromatophore orci s arms and horn filled with colorless 
cytoplasm (osmic vapor): Novem 9. 
Fics. 9, 10. Arms empty, ‘olen cytoplasm extending into posterior 
horn (osmic vapor). 
Fic. 11. Anterior polar view of similar cell, living. 
Fic. 12. Arms and horn nearly empty (osmic vapor). 
IG. 13. Posterior is view of similar cell, living, showing typical re- 
ia positions of organs as in Fic. 7; a large colorless cytoplasmic region 
und the nucleus. 
1G. 14. Older cell showing no trace of arms. 
Fic. 15. Cell from old culture with only a Snes of lateral arms; 
stigma = pyrenoid lying underneath the nucleu 
Fic. 16. Senescent = with contracted RES preparing to form an 
pean hae December, 1919 
Fic. 17. Young cell siete nucleus posterior to pyrenoid. 
Fic. 18. Posterior polar view of similar 
Fic. 19. Fi irst division of motile cell; 10:30 P. M. (osmic vapor). 
ed esent 
FIGs. 22-27. a. stages in division resulting in eight zoospores 
linen IgIg): . 22 at 2:40 P. M.; FiG. 23 at 3:40; FIG. 24 at 4:50; 
FIG. 25 at 5:30; a IG. oe at 6:20; Fic. 27 at 7:40. The zoospores escaped 
Stig Petia 
PLATE 4 
BRACHIOMONAS SIMPLEX Haz 
Drawn 29 June—4 July, 1920, Aslan: Norw. 
Fics. 28, 29. Typical mature vegetative cells: in Fic. 29 ae stigma lies 
slightly cade 
Fic. 30. Anterior polar view of similar cell. 
