CIRCULATORY SYSTEM 



361 



(v. c), placed between the nephridia, whence it is taken to 

 the kidneys themselves {np/i. v), thence by afferent branchial 



art. 



Fig. 96. — Diagram of the Circulatory System of Anodonta. 



The blood received from the auricles (aw) is pumped by the ventricle 

 (f) into the aorta {ao) and thence passes to the mantle {,art.^) and to 

 the body generally (ar/.^). 



The blood which has circulated through the mantle is returned 

 directly to the auricle : that from the body generally is collected into 

 the vena cava (f. c), passes by nephridial vems (npA) to the kidneys, 

 thence by afferent branchial veins {a/, br. v) to the gills, and is returned 

 by efferent branchial veins («/". br. v) to the auricles ; pc, pericardium. 



(From Parker and Haswell's Zoology. 



veins {af. br. v) to the gills, and is finally returned by efferent 

 branchial veins (ef. br. v) to the auricles. The mantle has a 

 very extensive blood - supply, and probably acts as the chief 



