408 DR. A. FARIIE ON THE STRUCTURE OF THE C1LIOBRACHIATE POLYPI. 
tion of a less mechanical nature, in accordance with which some are swallowed and 
others rejected. In the act of swallowing- the mouth is closed by the constriction 
below the tentacular ring-, and the sides of the pharynx being- brought into apposition, 
principally by the action of the part already alluded to, the particles are forced 
through the cardia, which projects into the pharynx with a nipple-like prominence 
(fig-. 8. A). 
As all below this point appears to be concerned more or less in the office of diges- 
tion, the stomach may be considered as commencing here, though in form it might 
rather resemble an oesophagus. The hepatic follicles, however, reach nearly as high 
as the cardia (fig. 7- «■)• If then the cardia be taken as the line of demarkation be- 
tween the pharynx or oesophagus and the stomach, without regard to its variable po- 
sition in different species, then it will be found that in some the pharynx is short and 
the stomach very long, as in the present instance, and in Valheria cuscuta ; whereas 
in Bowerbankia, where the cardia is low down, the reverse obtains, and the pharynx 
is of great length, while the stomach is comparatively short. 
Those who would follow out the analogy which undoubtedly exists between these, 
animals and those of the class Tunicata, and would compare the pharynx in the pre- 
sent case to the respiratory sac in Ascidia, might contend that the upper aperture of 
the pharynx being analogous to the entrance to the respiratory sac in Ascidia, then 
the lower aperture should be called the mouth, as being placed at the bottom of the sac. 
As, however, the pharynx is here certainly an organ for the reception and deglutition 
of food, and only probably concerned in respiration ; it would be more consistent to 
use the names as I have applied them ; the upper and lower apertures being respec- 
tively mouth and cardia, while the intermediate space may be designated from its 
probably double function, respiratory pharynx. The distinction, if contended for, 
would be at best but one of names and could not improve the analogy. 
The stomach is not furnished with a gizzard in this species. The intestine forms 
a considerable elbow at its origin, and is short and wide, terminating- not as in other 
cases near the tentacular ring, but about midway up the body, at a point opposite the 
base of the setae (fig. 7- «•)* 
A very singular organ (figs. 16, 17 and 18. b.) was frequently observed consisting of 
a little flask-shaped body situated between the base of two of the arms, and attached 
to the tentacular ring by a short peduncle. The cavity in its interior is lined with 
cilia which vibrate downwards towards the outer, and upwards towards the inner side; 
it has an arrow neck and a wide mouth, around which a row of delicate cilia are 
constantly playing. No flow of fluids could gver be detected through it, nor did the 
use of carmine assist in showingwith what parts the cavity in its interior might com- 
municate. From the circumstance that it is more frequently absent than present, it 
cannot be an organ of vital importance to the animal ; and it is too intimately blended 
with the sides of the tentacula and too constant in its position to be regarded as a 
parasite. Does it indicate a difference of sex ? 
