56 THE PHYSIOLOGY OF THE COMMON CRAYFISH. 



n broad i>late, liriiry on its inner surface, which enters 

 into the Literal wall of the cardiac chamber. 'I'here are 

 various other smaller skeletal parts, but the most im- 



FiG. 10. — AsfacusfluriatiUs. — Long-itudinal section of the stomach (x 4). 

 f, cardiac ossicle; ccr, ca;cum ; c.2>.r. cardio-pyloric valve; en. cushion- 

 shaped surface ; lig, hind-gut ; hp. aperture of right bile duct ; Ip, 1 

 lateral pouch ; It. lateral teeth ; vxj, mid-gut ; mt. median tooth ; «>.?, l 

 oesophagus ; j), pyloric ossicle ; pc. pterocardiac ossicles ; y;/'. prepy- 

 loric ossicle ; lie. urocardiac process ; r', median pyloric valve; v^, {| 

 lateral pyloric valve; ^.position of gastrolith; -r, zygocardiac ossicle. 



portant are those which have been described ; and these, | 

 from what has been said, will be seen to form a sort of I 

 hexagonal frame, with more or less flexible joints at the , 

 angles, and having the anterior and the posterior sides |j 



