MM. Kowalevsky and Barrois on Anchinia. 5 
formed by the cavity of the peduncle (cp), the other placed 
behind the upper part of the pharyngeal sac (cs) ; further, 
we must reckon as forming part of the general cavity the 
spaces /s,/7, bounded by the lateral expansions of the cloaca, 
the former empty, the latter lodging the digestive tube and 
the genital organs. 
4, Pharyngeal sac.—The pharyngeal sac, which, of itself, 
occupies at least two thirds of the internal space, has, like the 
whole body, a much elevated and abbreviated form; its ven- 
tral portion is occupied by the endostyle, which is very short 
in accordance with the general form. At its posterior portion 
are placed the branchiz, in the middle and towards the upper 
part of which the mouth opens. Lastly, it is traversed through 
nearly its whole extent by a vibratile line (/ v), which ter- 
minates at the top of the dorsal surface in a spiral, which at 
this point forms a special organ, sp. The nervous ganglion 
and the vibratile pit are situated a little in front of this spiral 
organ. 
5. Special organs. a. Ciliary band.—The vibratile band as 
usual surrounds the incurrent orifice; but in Anchinia it is 
easy to trace it to a great distance on each side. Above it is 
seen to continue beyond the vibratile (olfactory ?) pit and as 
far as the upper part of the pharyngeal sac, where, becoming 
recurved, it unites with the band of the opposite side, sp, 
forming at this point the spiral organ already mentioned ; in 
the middle of the spiral formed by the recurved extremity of 
the vibratile band, the wall of the pharyngeal sac gives off a 
small cecum which projects into the general cavity and con- 
sists of peculiar cells, smaller than in the rest of the wall and 
furnished with very strongly refractive nuclei (fig. 8, sp). 
The same organ exists in Doliolum, in which it likewise 
forms the extremity of the ciliary band, but does not occupy 
the same situation; it is nearer the incurrent aperture, and 
in front of the nervous ganglion and the olfactory pit. 
Voet has already described it in Anchinia under the name 
of the “ lacet recourbé en crochet.” 
In the opposite direction the vibratile band reaches the 
endostyle, curves in order to follow it in its whole length, and 
then rises at its other extremity, to be continued in the median 
line, between the two branchie, to lose itself in the mouth, 
where, no doubt, it gives origin to the spiral furrow, so well 
described by Vogt. (‘‘ In the anterior part of the digestive tube 
there is a spiral cord which descends along the cesophagus, 
* commencing from the mouth, and terminating near the stomach 
by becoming confounded with the general lining of the sto- 
machal cavity.’’) 
