Fig. 13. — Astacus flnviafilh. —The alimentary canal and livers seen from 

 above (nat. size), bd, bile-duct ; ccs, caecum ; cs, cardiac portion of 

 stomach, the line pointing- to the cardiac ossicle ; luj, hind-gut ; my, 

 mid-gut ;^7f. pterocardiac ossicle ; 7«, pyloric portion of stomach, 

 the line pointing to the pyloric ossicle ; r, ridge separating mid-gut 

 from hind-gut ; zc, zygocardiac ossicle. 



