rUNATELLA GRACILIS, A FRESH -WATER I’OLYZOAN. 
11 
'Ihe interior of the polyp-bell is mainly occupied by tlie alimentary apparatus, 
riie mouth of the bell converges in a wide funnel-like manner to the pharyn.x, whicli 
occupies the venti-al or shorter side of the bell. When the tentacles are retracted, 
they are doubled on themselves and withdrawn into the funnel-like month of the hell, 
and the collar marked with circular fibres contracts in a circular baud around them. 
The mouth of the bell is lined with ciliated e])ithelium, and the cilia produce visible 
currents convergent to the bottom of the funnel or pharynx. From the latter a 
cylindrical tubular oesophagus is extended upwards along the shorter or ventral side 
of the body, and turns dorsally to open into the stomach, 'fhe walls of the pharynx 
Urnatella, with stem of four seg- 
ments with polyp-head giving off a 
branch, with a ]iair of secondary 
branches. 
0. PedicclUna, from NewiHtrt harlmr, 
I?. I. 
and irsoplinKUS nre formed of rhort columnar ciliated epithclinm. 'I hc inovcincnt- 
of tlie cilia nre directed into the stomach. This is a capacious organ, rvliich nearly 
occupies half the interior of the polyp-bell, arrd always appears more or less tilled 
with liquid and solid materials, which are kept in incessant motion. The stomach n, 
shape resembles a retort or still, with an alembic, and consists of a large oval tlnek- 
walled receptacle with a conical prolongation or pylorus extended from the former 
at its lower part downward on the dorsal or deeper side ol the body. lheu|qa.r 
part of the stotnach is flattened, and is connected with the bottom of the po y,ebcl 
L a sort of button, which ap,Kars to be a co.rtinnation of the nttenor 
o? the sten, of the polvp. The lateral walls of the stomach are forme, I o tlnek 
lu ttnar epithelium : the upper part and the sides of the pylorus of a much tlnnner 
