178 Mr. A. Hancock on the Anatomy of the 
two former, however, both the cesophagus and stomach are shorter 
than they are in the latter genus. 
In all these genera no disturbance of the parts of the alimen- 
tary canal takes place on the retraction of the polype: the ani- 
mal sinks into the cell with the cesophagus, stomach and intes- 
tine erect as they were when the tentacles were exserted and in 
full play. Not so however in Paludicella, Pl. IV. fig. 2; mm this 
genus the alimentary canal is doubled upon itself when the po- 
lype is retracted ; and moreover the parts are somewhat modified, 
approximating this form more closely to that of the marine 
species. 
When the animal of Paludicella is protruded, the cesophagus, 
fig. 1 A, is observed to be long and slender, and to have a di- 
stinct pharyngeal dilatation at the commencement, where vibra- 
tile cilia can be seen in vigorous action. It communicates with 
the upper extremity of the stomach by a circular orifice, fig. 2/f. 
The stomach, fig. ] 2, is rather short, considerably enlarged above 
and tapering to the inferior extremity, where it is rounded: the 
walls are thick, and apparently filled with yellowish brown co- 
loured granules, probably hepatic as in the marine species. The 
intestine, 7, arises from the superior extremity close behind and 
a little above the cardia. The pyloric opening is well defined and 
circular ; soon after its origin the intestine is suddenly enlarged, 
forming an oval swelling, 4, in which the feeces may be seen col- 
lecting ; it contracts above this swelling, and continues afterwards 
for nearly its whole length of equal diameter ; it passes upwards 
in a straight line parallel with the cesophagus, but unattached to 
it, and terminates in a rounded anal extremity, /, immediately 
below the base of the tentacles where it perforates the tentacular 
sheath. The upper end of the stomach, close to the pyloric ori- 
fice, is furnished with vibratile cilia, and here the alimentary 
matters may be seen rapidly rotating by their influence. The 
feeces are formed into small pellets, which, coming from the en- 
larged portion, pass up the imtestine and are expelled at the 
anal orifice. The whole of the canal is as highly irritable as m 
the other species ; the stomach undulating from above downwards 
in the same manner, and the cesophagus is equally expert in 
transmitting food to the stomach. But neither in Paludicella 
nor in the species before alluded to does the pharyngeal swelling - 
exhibit in any marked manner the sudden puflings and contrac- 
tions so conspicuous in the marine species, and noticed originally 
by Dr. Farre. 
On retraction of the polype, the alimentary canal of Paludicella 
is doubled upon itself im much the same way as in Bowerbankia. 
The basal dise of the tentacles is then brought down as far as 
