HELIX 



3. View of the respiratory chamber, opened by a cut extending from the respiratory orifice 

 across to the left side, and by another cut on the right side passing backwards along the extreme 



ight-hand limit of the chamber, so as to leave the anus, rectum, and kidney in continuity with the 

 oof. Floor of the respiratory chamber formed by the thin dorsal integument ; rectum ; kidney ; external 

 opening of kidney ; duct of the kidney by the left side of the rectum ; auricle and ventricle of the 

 icart lying in the pericardium ; blood-vessels of the respiratory surface. 

 N.B. Remember that rectum, kidney, and heart are turned back and are now seen inverted. 



4. Notice that the partition between the pericardium and the kidney sac is indented by a shallow 

 )ay. At the end of this bay is the reno-pericardial opening. Open the pericardium and pass a fine 

 uarded bristle through the opening into the kidney. 





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