282 THE ANATOMY OF INVERTEBRATED ANIMALS. 



attached by six ligaments, corresponding with tlie ala3 of the 

 heart in insects, but not, like them, muscular. Except by 



f? /if 17/ f f 



Fig. 7i.—Astac>(S, Lon^itiuiinal Section.— I. II, III, Stern?? orfirgt. scrond. and third 

 pomitcs; oe, oesophagus; lb, labrum : I. nietastoma ; 6-, membranon!* p'lrt of the 

 stomach; t\ cardiac ossicle; />('. pterocardiac ; //c, urocardiac ; c/, lateral cardiac; 

 /), cardio-pyloric valve ; pi. inferior pyloric valvular apparatus; m, anterior irastric 

 nuxscle ; ?n*. insertion of posterior gastric muscles; pc, proceplialic processe-^ ; 

 f//. openini,' of hepatic duct ; v, pyloric caecum ; i, k, intestine ; gn, testis ; fjv'. (/ii^\ 

 vas deferens ; C. heart ; ao, ophthalmic artery ; aa, antennary ; ah, hepafic ; as, 

 sternal ; ap, superior abdominal artery ; 6, cerebral j,'anglia ; sg, azygos visceral 

 nerve. 



these ligaments, and by the arteries, Avhich pass tlirough it, 

 the walls of the pericardial cavity, or blood sinus (for such it 



