THE STOMACH OF THE CRAYFISH. 



53 



X)lace, to the very remarkable and complicated apparatus 

 >Yliich has already been spoken of, as a sort of gastric mill 



Fig. 9.—Astaciis fliiviatilis.—X, the stomach with its outer coat removed, seen from the 

 left side ; B, the same viewed from the front, after removal of the anterior wall ; 

 C, the ossicles of the gastric mill separated from one another ; D, the prepy- 

 loric ossicle and median tooth, seen from the right side ; E, transverse section of 

 the pyloric region along the line x?/ in A (all x 2). c, cardiac ossicle ; cpr, cardio- 

 pyloric valve ; Ip, lateral pouch ; U, lateral tooth, seen through the wall of the 

 stomach in A ; mg, mid-gut ; mt, median tooth, seen through the Avail of the 

 stomach in A ; ces, oesophagus ; p, pyloric ossicle ; pc, pterocardiac ossicle ; 

 ■pp, prepyloric ossicle ; uc, uro-eardiac process ; t, convexities on the free surface 

 of its hinder end ; v^, median pyloric valve ; zc, zygocardiac ossicle. 



ov food- crusher ; and, secondly, to ^filter or strainer, 

 whereby the nutritive juices are separated from the in- 

 nutritious hard parts of the food and passed on into the 



intestine. 



