242 Trochosphsera sequatorialis. By Herr Semper. 
for the introduction of food, whilst the first is only a rotatory 
organ. 
Claparede, the excellent zoologist of Greneva, whose early death is 
much to be deplored, lately showed that this mouth fringe occurs 
in all other Rotatoria as well. The mouth is succeeded by a funnel- 
shaped thickly fringed cavity, joined by the mastax (Ih) furnished 
with the characteristic jaws of the Rotatoria (8). With this mastax 
is connected a longish, thin pharynx (Id), which passes straight 
inwards, and at the place of passage into the stomach itself (1 e) 
gives rise to two gastric glands (Ir), such as occur in other Rotatoria 
in the same place. The thick hair in the pharynx is in the direc- 
tion of the stomach. The latter is broad, cylindrical, and has a 
thick coating formed by large colourless cells ; it stretches a little 
over the (1 e) middle of the oral hemisphere, turning a little 
towards the aboral, then bends sharply round and passes in a 
straight line towards the anus. The last part of the intestines, 
that can be perfectly separated from the small final intestines {9 a) 
by a muscular sphincter, must be considered as the cloaca (1/, 9 c), 
since the excretory ducts (9 n, n') as well as the simple oviduct 
(9 e) and a contractile vesicle are in connection with it. The final 
intestine is thickly covered with hair as well as the stomach ; the 
direction of the hairs in the former is towards the latter. 
Although the contractile vesicle at the cloaca certainly is no 
continuation of the two excretory ducts, yet I suppose it must be 
compared with the excretory bladder of the other Rotatoria. Its 
contents are always of a glassy brightness, it is free from cilia, and 
its contractions are not rhythmical, their duration being between 
five and fifteen seconds. The contraction takes place by jerks. 
Although the colourless contents of the bladder cannot be followed 
farther in its motions directly, yet from conditions of contraction or 
expansion of the cloaca and intestines connected with the narrowing 
of the bladder, we may conclude that the liquid coming from that 
bladder does not — or at any rate does not always — empty itself 
away, but passes straight into the stomach. For upon every con- 
traction of the bladder an expansion of the cloaca immediately 
follows, and on the close of the latter immediately, with perfect 
regularity, an opening of the sphincter of the final intestine occurs, 
and an expansion of the latter. The expansion of the cloaca is not 
simultaneous in all its parts ; but the part of it where the bladder 
leads into it is first expanded, and the expansion then is propa- 
gated in waves till the commencement of the intestines, and passes 
on into this in the same way. This always takes place whilst the 
anus is perfectly closed. The coats of the intestines and cloaca 
remain expanded a short time, that of the first for a longer time 
than that of the latter, which soon falls together again. Lastly, if 
