
rior extremity is very broad and shows aslight 
convexity, extending to the antero-lateral 
blunt angles; the posterior end is also blunt; 
there is only a narrow periplastic layer of 
ectoplasm maintaining a more or less unchan- 
ging outline ; endoplasm alveolar. At the two 
latero-anterior angles two cytostomes; these 
are larger and set wider apart than in Waskía 
intestinalis, they open outwards and in front 
and are as broad as they are long, about 
a fourth of the greatest width of the cell. 
From each cytostome emerge two flagella 
which are not quite half as long as the body, 
One of the flagella is thick, undulating and 
behind the other, which is slender and not 
59 

Ar 

undulated; the thick one is perpendicular to 
the axis, 
The cytostomes open and shut in syn- 
chronic and alternating movements when; 
the prehensile apparatus is at rest they 
are both equally open, whereas when one 
of them is wide open, the other is corres- 
pondingly shut. These variations give one 
the impression that the plasm between them 
has a pendular oscillatory motion which 
controls the alternative opening and shutting. 
Dimensions Length about 14 u Width 
about 12. 
Habitat: Coecum of Cebus caraya HUM- 
BOLDT. 
