LOSOSOMA. 361 



opening is seen to be furnished with two lips^ one ventral [k) 

 and button shaped, the other dorsal {I), recurved like a hook, 

 and projecting freely iato the vestibule.^ The inner surface 

 of these lips is covered with fine, short cilia, which extend into 

 the narrow, curved canal of the cesophagns {m). The latter 

 passes down the ventral side of the body, and is also enclosed by 

 thick walls. From the cesophagus the vibratile epithelium ex- 

 tends over the whole internal surface of the intestine, and is 

 always so arranged that the alimentary matter is made to revolve 

 rapidly in the various cavities. 



At the base of the body, close to the stem, the oesophagus 

 bends sharply upwards, and opens into a round, thick body — 

 the stomach (n). When it is viewed in front, a nipple-shaped 

 prominence is visible, placed posteriorly towards the sides in the 

 middle, which is the opening into the oesophagus — the cardiac 

 valve — and near this there is almost always a very vigorous play 

 of cilia. The true cavity of the stomach is above, surrounded 

 by very thick walls, with radiating striae, and lined internally with 

 granular cells, of a yellow colour, which always contain small 

 drops of oil, and are arranged in radiate fashion (PI. XXII, fig. 3). 



The author adopts the common view that these cells have a 

 biliary function ; but he also regards them as absorbents. In 

 polypides that have been fed with carmine, they assume an 

 orange or scarlet tint, clearly showing that there has been an 

 absorption of colouring matter, which has modified the ordinary 

 amber-yellow of the cells. This orange tint continues long after 

 all the carmine that had been swallowed is evacuated, and has a 

 diffused appearance, as if a fluid might have pervaded the cell. 

 In no other portion of the intestine is the slightest trace of 

 coloration apparent. 



The pyloric orifice, opening from the digestive cavity into the 

 intestine, is placed on the dorsal wall of the stomach, at a rather 

 higher level than that of the oesophagus. The intestine proper{ g) 

 lies close upon the dorsal wall of the body, and is divided into 

 two pyriform compartments, connected by a short and narrow 

 tubular passage. The first of these compartments represents 

 the middle intestine, and the second, the rectum (h). 



The rectum is generally so completely closed at its upper 

 extremity as to show no trace of an opening. From time to 

 time, however, a narrow orifice makes its appearance in the thick 

 wall at the summit, exactly opposite the centre of the tentacular 

 crown, through which the faecal matter is discharged into the 

 vestibule. After its expulsion the opening entirely disappears. 



' Judging from Nitsclie's figures, there seems to be no trace of these 

 lip-like appendages in PediceUina ; but the dorsal one, which is the larger 

 and more conspicuous, has its representative in Rhabdopleura, according to 

 Sars. — Transl. 



