86 THE PH¥LOGENY OF THE GENUS BRACHIOMONAS 
the cilia, and tapering to an acute point at the posterior end 
Fic. 46). Older individuals, kept for two weeks or longer in 
hanging drops, show the cell-wall much thickened, or the pro- 
toplast contracted and rounded posteriorly and produced into 
more or less of a beak at the anterior end (Fics. 47, 48). The 
broad truncate anterior papilla of the cell-wall (Hautwarze) 
impresses me as being rather more prominent than shown in 
Fics. 46-50. CHLAMYDOMONAS CAUDATA Wille 
46. Young cell, “dorsal view,’’ showing typica Iposition of nucleus, stigma, 
and pyrenoid. _ a1 Older cell with thickened wall. 48. Similar cell in 
“lateral view.’’ 49. Typical arrangement of daughter cells. 50. Unusual - 
arrangement of daughter cells. All, x 720, approximately. 
Wille’ s (15) figures, and the red eye-spot, first described as 
langgestreckter’ and again as ‘oval oder stabférmig,’ was in 
my mature specimens always a strongly oval disc, sometimes 
with an anterior pointed end, showing its thinness in the fact 
that the edge view was narrowly linear. These differences 
may be readily accounted for by differences of magnification 
during observation. The longitudinal streaking of the chro- 
matophore noted in the original description, and even intro- 
duced in Wille’s key to the species, was never distinguishable 
in vigorous material of either this species or C. subcaudata in 
1920; only certain individuals kept for ten days or more in 
