252 MR. F. D. DYSTER ON PHORONIS HIPPOCREPIA. 
situated as in the Polyzoa, in lines, and not (as in many tubicular Annelids) all over the 
surface. They exhibit no trace of thread cells, and do not appear to be used as organs of 
prehension, but provide the food required by the worm by the current produced by the 
cilia. The body is not ciliated externally. Below and between the rami of the lophophore 
are two somewhat sigmoid ridges, which are the terminations of the oviducts. In some 
individuals, and always in large ovigerous specimens, at the posterior inner margin of the 
concavity of the lophophore, are seen two nearly circular lips, apparently with a perfora- 
tion in their centre. Their use I cannot indicate. They may possibly be the terminations 
of the sperm-ducts; but as when the worm is in a position to exhibit the protrusion of 
the ova, these organs are hidden, I am unable to say whether any action occurs in them 
simultaneously with the deposition of eggs. The integument of the body is composed of 
a very delicate epidermis, beneath which are bundles of longitudinal muscular fibres, 
connected transversely by others, shorter and more delicate. The length of the largest 
specimens dug out from the rock would vary from I to 3ths of an inch. 
Between the two rows of tentacles, on the neural side of the body, but nearer the 
hæmal row, is the mouth, which is somewhat elliptic, ciliated, and surrounded by a mus- 
cular sphincter, and covered by a delicate transparent marginated crescentic lip, attached 
by its concave edge to the convex portion of the lophophore. The mouth opens into a 
delicate expansible (non-ciliated ?) æsophagus, which occupies the middle of the body. I 
have failed to detect the bands of areolar tissue alluded to by Dr. Wright as the stays of 
the alimentary canal. Just below the portion of the body protruded from the tube, the 
cesophagus opens, apparently through a sphincter, into an oblong stomach, richly 
ciliated, in which the food revolves rapidly in pellets, as in Pedicellina. What lies beneath 
the stomach I am unable to state decisively. ‘The lower part of the body is so deeply — 
imbedded in the hard rock, ahd its substance so fragile, while the tube is comparatively 
so tough, that very many hours of effort failed to extract one in perfect integrity ; and 
the lower portion is so opaque that its walls do not permit its contents to be seen. I 
believe, however, that the stomach terminates in a very capacious intestine, which, filled 
with fæces, occupies the lower portion of the body, and which, traversing the whole tube 
and gradually narrowing, ascends again to terminate in a circular anus lying a little 
above, behind, and between the ridges made by the oviducts between the extremities of 
the rami of the lophophore The intestine lies above the cesophagus and the great 
blood-vessel, but beneath the oviduct. It is exceedingly delicate in structure, and can 
ecarealy be made out except by its contents. It is not ciliated. The fæces are voided by 
jerks, in fusiform pellets connected by slender filaments, and frequently equal in length 
the whole exposed portion of the body. 
The only organs to which hepatic functions could be attributed were some coloured 
cells on the walls of the stomach. 
puit Fe yen tas but this part of the organization demands further 
- "Sade ita y die that the two obscure organs mentioned as being present 
no eye-spots ; iu à : the ee hophore may be cesophageal ganglid ee 
Above the œso "e menge N sensibility to the influence of light. 
phagus, and attached to it by one margin, lies the great blood-vessel, 
