690 
ZOOLOGICAL LITERATURE. 
the arched side is most remote from the surface over which the 
animal moves. 
b. Moxon asserts the presence of a median dorsal feeler in 
MelicertUy FlosculariUj Metopidia, Limnias, and Pterodina ; also 
of lateral feelers in Limnias and Floscularia, and probably in all 
the stationary genera. In the two forms just mentioned the 
lateral feelers are symmetrically placed towards the ventral 
aspect^j on slight conical elevations^ close to the part Avliich 
forms the upper end wlien the lobes are retracted.^^ 
The stalked lateral feelers of Melicerta have long been known, 
but no one has hitherto described the median feeler, which is 
sessile on the back of the head, behind and between the eyes 
in the young, and on the same side of the body as the cloaeal 
opening. For these reasons it is, doubtless, homologous to 
the stalked dorsal feeler of Philodina. 
c. The anterior portion of the alimentary eanal is more 
complex in Floscularia than in any other Rotifer. A highly 
irritable cilium -clothed sphincter of irregular outline separates 
the oral vestibule from the so-called pharynx with strong 
muscular walls, which immediately precedes the unusually large 
gizzard or manducatory cavity. This is furnished with a 
peculiar apparatus, the tube valve,'^ entirely mistaken by pre- 
vious observers. It eonsists of a long thin- walled, flattened, 
cilium-lined tube,'" continuous above with the margin of the 
pharyngeal opening, while its opposite end waves loosely about in 
the interior of the gizzard. In three instances Moxon has seen 
this tube discharge its contents by a process of complete eversion, 
involving the entire alimentary canal in front of the gizzard. 
The prey, which the pharynx receives by an act of true degluti- 
tion, readily passes through the tube into the cavity of the 
gizzard. From this, however, its return, save at the will of the 
animal, is, by the very same means, rendered impossible, the 
closely- approximated walls of the now flattened tube impeding 
all progress in an oral direction. The presence of such a valve 
Moxon believes to be unknown elsewhere in the animal kingdom. 
In Euchlanis dilatata there exists a cloacal sphincter, just 
below the ovarian and intestinal openings. This sphincter 
being closed, Moxon saw the contents of the contractile vesicle 
injected into the intestine when packed with fecal matter so 
that its cilia were quite motionless. On entry of the foreign 
liquid, the action of the cilia soon commenced, and, being 
seconded by renewed efforts of the contractile vesicle, quickly 
succeeded in effecting a complete defecation. 
d. Moxon has discovered a water-vascular system both in 
Limnias and Floscularia. In the latter genus its vessels are 
relatively of very small diameter. He has seen nothing of the 
peculiar cii’culating system described by Gosse, but the granules 
