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1884.] Infusoria from Putrid Waters. 139 
specific name. When viewed dorsally, consequently in transverse 
optical section, the body is ovate in outline. In its lateral aspect, 
as is shown in the figure, it exhibits a superficial differentiation 
into an anterior narrower body-half and a rounded, very con- 
spicuously widened and inflated posterior portion. When mature 
it measures ,j; inch in length, ,}, in. at the widest part of the pos- 
terior body half, and yd) in. at the greatest width of the anterior 
portion. 
The surface is obliquely grooved, apparently in two directions, 
this double striation being much more conspicuous in the young, 
as is also the case with Tillina saprophila. In color it is a deep 
amber, The tint varies in depth, however, changing with the 
color of the infusion and, to a certain extent, with age, the young 
usually being paler than the adults. The granulate endoplasm 
encloses many large granular corpuscles, seemingly formed of 
agglomerated food particles, almost as abundant in those just 
escaped from the cyst as in the older animals. The large ovate 
nucleus is located above the median line near the center of the 
dorsum. The single contractile vesicle is situated close to the 
Posterior extremity and to the right. It pulsates, as in the pre- 
_ Ceding species of the genus, once each fifteen seconds, The anal 
aperture seems to be rather indifferently placed either above or 
below the pulsating vacuole. But I may have misinterpreted 
this, as its appearance is always sudden and unexpected, the ani- 
mal being in rapid movement at the same time, and the contrac- 
tile vesicle probably collapsed and invisible. The ovate oral 
‘ aperture is placed obliquely near the center of the left latera} 
a margin of the ventral surface. The succeeding rather capacious. 
_ but short and slightly recurved pharynx is entirely ciliated, the 
Cilia being of course shorter, but apparently much coarser, than 
e long fine vibratile hairs of the cuticular surface. To actually 
See the individual pharyngeal cilia is no small matter, demanding 
_ 20 slight amount of patience even after the restless creature has 
their seemingly greater size may therefore be 
’ raed both with this; and the preceding Tillina, as I have 
___ 10 instance been able to see them in the recently-killed infu- 
» while those of the cuticle are then readily resolved. 
Movements resemble those of T. saprophila, the creature 
the ba upon one side, usually the left, when quietly feeding on 
_ »acteria that seem to be a favorite food. When these plants are 
Its 
