136 Notes on some apparently undescribed — [February, 
the latter event differing in form so conspicuously from the mature 
animal that, before the life-history had been traced, they were 
mistaken for another species and described as such in manuscript. 
The act is performed without immediate conjugation; whether in 
the instances observed there had been a remote union, I of course 
do not know. 
Individuals have several times been so accommodating as to 
enter the field of the objective just before the beginning of the 
first stage in this reproductive act, thus affording me an oppor 
tunity to follow the changes with ease. The body is soft and 
flexible, but, except immediately prior to encystment, is not 
changeable in shape. At that time, however, the animal assumes 
a spherical form, and prepares a cyst so delicate and transparent 
that ordinarily it is invisible after its evacuation; but occasionally 
it collapses as an indescribable exuvium containing several bright 
bubble-like spots, and becomes for a very short time slightly 
Fig. 3. Fig. 4. 
_ fillina saprophila, n. sp. Fic. 3-——Immature form, x 960. Fic. 4.— Mature 
infusorium, xX T50. 
amæœæboid. Fission is accomplished within this sac, and I have™ 
one or two instances observed a binary division without the forma 
tion of an enclosing membrane; but in every case it seems that 
the divided surfaces become the ventral, The process, at leat 
when four zooids are the result, consumes about two hours pics 
the assumption of the spherical form. The young force ie 
way from the cyst through a small opening visible only 12 a 
effect upon the shape of the emerging creatures. A small kn 
like projection first appears, and as the animal urges itself throug! 
the aperture, a narrow and sharply defined constriction pe 
successively over the whole length of the body, each of the li poe 
animals emerging through the same opening. The young ©” 
the old differ, as shown in lateral view in Figs. 3 and 4, the ont 
being the mature form, in which the dorsal surface, as seen in P oe 
file, is much more strongly and evenly convex, and the “aa 
more flattened, than in Fig 3. In the infusion, forms intermediat 
