450 Report or the State Geologist. 



the marine forms there are long vibratile cilia near the pyloric 

 orifice of the stomach. 



The oesophagus and stomach are very irritable, and the 

 stomach is in constant motion whenever the animal is exserted . 

 When food is received the contraction of the stomach is very de- 

 cided ; the food remaining in the stomach a very short time, 

 then descending with great rapidity. In the gizzard of marine 

 forms they are subjected to a sort of crushing process, the two 

 dark bodies previously spoken of, being brought in apposition 

 {^g. 16, h). After remaining in the gizzard a very short time, the 

 food passes into the stomach, where it is rolled about in a peris- 

 taltic motion, being frequently regurgitated into the gizzard. In 

 the upper portion of the stomach, near the pyloric orifice, the 

 food assumes a rotary motion from the action of the vibratile 

 cilia. In some species with very clear walls the motion of the 

 cilia can be very plainly seen by microscopic observations. The 

 alimentary matter passes from the stomach by the pyloric orifice, 

 and in the large portion of the intestine, near this orifice, it is 

 formed into little pellets of excrementious matter, which, by the 

 contractions of the walls of the intestine, is carried to the anus, 

 and passing out is carried away by the current caused by the 

 action of the cilia of the tentacles. 



Fig. 20. Eschara cervicornis. f, Tentacula: b, Pharynx; /.Filiform appendages; d, Stomachal 

 dilation; i, Intestine; o, Oral aperture ; m, Muscles (after Jones). 



Tentacles. 



The tentacular crown of the Brtozoa consists of two portions, 

 a disc surrounding the mouth, the lophophore, and the tentacles 

 which are borne upon the margin of this disc. 



