THE STOMACH OF THE CRAYFISH. 



53 



l)lace, to the very remarkable and complicated apparatus 

 ^vhicll has already been spoken of, as a sort of gastric mill 



Fig. 9.—AstcKus JluviatiUs.—A, the stomach with its outer foat removed, seen from the 

 left side ; B, the same viewed from the front, after remo\-al of the anterior wall ; 

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

 loric ossicle and median tooth, seeii 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- 

 pyloric valve ; Ip, 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 ; 

 pj), prepyloric ossicle ; vc, uro-eardiac process ; t, convexities on the free surface 

 ot Its hinder end ; r', median jjyloric valve ; zc, zygocardiac ossicle. 



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

 Avhereby the nutritive juices are separated from the in- 

 nutritious hard parts of the food and passed on into tlie 

 intestine. 



