Fig. 5.—Astacus fluviatilis— A male specimen, with the roof of the 
carapace and the terga of the abdominal somites removed to show 
the viscera (nat. size) :—aa, antennary artery ; ag, anterior gastric 
muscles ; amm, adductor muscles of the mandibles; cs, cardiac 
portion of the stomach ; gg, green glands ; /, heart; hy, hind gut, 
or large intestine ; Zr, liver; oa, ophthalmic artery ; pg posterior 
gastric muscles ; sae, superior abdominal artery ; 1, testis ; vd, vas 
deferens, 
