442 



PHYLUM MOLLUSCA 



running along the right side of the pulmonary chamber, and 

 opening close beside the anus. There are two sources of 

 blood supply to the kidney — {a) from the pulmonary 

 chamber, and {b) from the heart by a renal artery. As in 



Fig. 251. — Dissection of snail. 



T., Short horn ; TT., long horn with eye ; N., cerebral ganglia ; S.G. 

 salivary glands on the crop ; F., foot ; M., coluniellar muscle ; V.C., 

 visceral coil ; O.T., ovotestis ; V., ventricle of heart ; R., rectum ; U., 

 ureter ; B.V., blood vessels returning to the auricle from the mantle ; 

 A., pulmonary aperture ; MA., edge of the mantle. 



most Other Molluscs, the kidney communicates by a small 

 aperture with that part of the coelom which forms the 

 pericardial sac. Thus, as in earthworm, lobworm, etc., the 

 coelom has a nephridial connection with the exterior. 



Reproductive system. — The snail is hermaphrodite, and 

 its reproductive organs exhibit much division of labour. 



