288 ONE OF OUR COMMON MONADS. 
ical to raspberry or even mulberry shape, the form shown in ek 
88 being the most common. 
I was unable to find any trace of a common investing mem- 
brane in either the larger or the smaller groups, nor do I believe 
that any such membrane exists in any true species of Urella. 
I was able to distinguish clearly two flagella, both arising from 
a point near the most elevated side of the base of the cone. The — 
Fig. 90. larger one was stif, 
arcuate with the con- — 
cave side toward a 
a Hartnack number nine. 
I am not certain as to the number of contractile vesicles 
of clear spaces would be seen in the body, but they W 
observed to contract. I do not 
wish, however, to speak with any 
degree of positiveness upon this 
point, as I was not able to keep 
a single monad in view long 
enough to satisfy myself, on ac- 
count of the constant revolution 
of the colonies. As regards the 
ingestion of food I have seen 
something, though not as much as I could wish, 28 * 
disputed question. I fed them with indigo which = 
and I frequently watched its ingestion. On a 
cessant motion, I was not able to satisfy my self of re 
of a definite mouth, but I did not see a single Í 
indigo being received at any point except very ie 
Fig. 91. 
