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Transactions of the Society. 
witli every part alert and ready for the prey, which it has no other 
means of capturing. At the moment of the victim’s entrance into the- 
cup the membrane is folded together, contracting closer and closer, as 
it struggles, until in some instances the pressure is great enough to 
crush the body of the animalcule into a diffluent mass of protoplasm. 
In other cases the Infusorian is directed, by the folds and the furrows, 
within the reach of the oesophageal ring, which suddenly gaps and 
snaps, and engulfs it with a gulp, transmitting it to the proventriculus,. 
where it may live for several seconds, as so often observed in various 
Infusoria. 
The tufts of setae within the cup, unlike the larger but similar 
setae of Floscularia, do not extend into the open water beyond the 
margin of the coronal cup, there to form a trap to lead the victims 
down to the buccal orifice, but are far below the margin, where their 
function must be to assist in retaining the prey near the oesophageal 
ring. Yet, although the Eotifer has no more active means of 
seeking its prey, small desmids and other naturally immobile objects 
are not rare within both the anterior and the posterior stomach. How 
they are obtained is not easily conjectured, unless these freely floating 
objects are carried toward and into the cup with the strong currents 
produced by the expansion of the contracted cup. This is the effect 
when the Kotifer is confined under a cover-glass, as I have repeatedly 
witnessed. 
The muscles of the cup are slender, and exceedingly numerous 
and complex in their arrangement. In Apsilus bipera they are 
comparatively few, and unusually large and robust. Their number, 
size, and arrangement may be of value in separating the species 
(figs. 1, 2, and 4). Several of the larger body-muscles are coarsely 
striated transversely. 
The entire mass of the internal organs is enveloped in a network 
of fine nerve-fibres, a minute ganglionic enlargement being present at 
the point of each anastomosis, the network extending between the 
membranes of the coronal cup, where it is even more luxuriantly 
developed than within the body. The primary or central nervous 
ganglion (g, fig. 1) is not situated within the substance of the coronal 
cup, as it is said to be in A. lentiformis Metsch., but in the frontal 
region of the dorsal body-wall, immediately behind the base of the- 
coronal cup, and just above the position of the oesophageal ring. It 
is an elongated, irregularly ovate mass of nucleated cells, placed 
transversely in the cervical region. It gives off* numerous fibres from 
its lateral poles. 
The young are essentially similar to those described from A. lenti- 
formis. 
Apsilus bipera Foulke, plate YI. fig. 4. 
In company with A. bucinedax I have taken several specimens of 
this species, but the only apparent differences between the two are in 
