THE STOMACH OF THE CRAYFISH. 



53 



place, to the very remarkable and complicated apparatus 

 which has already been spoken of, as a sort of gastric mill 



P .c 



Fi3. 9. Astacus fluriatilis. A, 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- 

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

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

 pylorie valve ; lp, lateral pouch : It, lateral tooth, seen through the wall of the 

 stomach in A ; ing, mid-gut ; mt, median tooth, seen through the wall of the 

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

 pp, prepyloric ossicle ; vc, uro-cardiac process ; t, convexities on the free surface 

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



or food-crusher ; and, secondly, to a filter or strainer, 

 whereby the nutritive juices are separated from the in- 

 nutritious hard parts of the food and passed on into the 

 intestine. 



