THE STOMACH OF THE CRAYFISH. 



53 



place, to the very remarkable and complicated apparatus 

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



Fig. 9. — Antaeus fltiviatilis. — A, the stomach with its outer coat removed, seen Trom 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 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 ; mg, mid-gut ; mt, median tooth , seen through the wall of the 

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

 PP, prepyloric ossicle ; iic, uro-cardiac process ; t, convexities on the free surface 

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



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

 whereby the nutritive juices are sej^arated from the in- 

 nutritious hard parts of the food and passed on into the 

 intestine. 



