36 



Natural History of Molluscous Animals : — 



In this singular and beautiful creature, the heart is situated in 

 the middle of the back, immediately under the skin. Its 



a. Veil; b, tentacula ; c, neck ; rf, organs of generation ; e, anus and another excretory 

 orifice j /, greater branchiae; g, lesser branchiae; h, margins of foot. 



oval and very thin auricle receives the branchial veins, which 

 trend towards it like the spokes of a wheel towards the nave, 

 and pour into it the purified blood, not by one or two, but 

 by numerous orifices. The opening from the auricle to the 

 ventricle is furnished with two very distinct valves ; and, as 

 usual, the latter cavity is more fleshy and opaque than the 

 auricle, of an oval form, and strengthened with small muscular 

 cords. Two principal arteries take their departure from it ; 

 one of which, proceeding forwards, gives branches to the sto- 

 mach, oesophagus, to the organs of generation, to both sides 

 of the back and foot, and lastly loses itself in the veil ; while 

 the other artery, directing its course backwards, is principally 

 distributed on the rectum and liver. The veins issuing from 

 this organ, and from the intestines, run in the sides of the 

 body, where, in conjunction with the veins returning from the 



