CIRCULATORY SYSTEM 361 



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

 the kidneys themselves (nph. v\ thence by afferent branchial 



art./ 



a.r-12 



FIG. 96. Diagram of the Circulatory System of Anodonta. 



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

 (v) into the aorta (ao) and thence passes to the mantle (art. 1 ) and to 

 the body generally (art. 2 ). 



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 (v. c), passes by nephridial veins (nph) to the kidneys, 

 thence by afferent branchial veins (of. br. v) to the gills, and is returned 

 by efferent branchial veins (ef. br. v} to the auricles ; pc, pericardium. 



(From Parker and Haswell's Zoology. 



veins (af. br. v) to the gills, a*nd 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 



