PLATE II. 



Mesenchytrceus harrimani sp. nov. 



FIG. i. Section through some epithelial cells lining the inner surface of the 

 sperm-duct at a point marked xx, near the opening of the pore. 



2. Nephrostome, viewed from the flat or ventral side. 



3. Nephrostome, side view. 



4. Diagrammatic view of the lower part of the male apparatus, from 

 dissection. The atrial glands are seen to be confined to one side of 

 sperm-duct. The arrangement of the glands in the bulb is merely 

 indicated. The bulb is thick and globular and quite opaque. 



5. Section through part of the epithelium near the male-pore from a 

 point marked x. The epithelial cells are separated by the narrow 

 ducts of the unicellular glands composing the atrial gland. These 

 ducts open between the epithelial cells. Other ducts open in the 

 lumen of the sperm-duct. 



6. Section through the epithelial cells lining the inner surface of the 

 sperm-duct at a point marked xxx. The epithelial cells are here thin 

 and long and not situated close together. They are furnished with 

 long cilia. The narrow ducts from the atrial glands are seen to open 

 between the epithelial cells. 



7. Section through the male-pore. Low magnification. 



