nephrostome
(noun)
 the funnel-shaped opening of a nephridium into the body cavity
Examples of nephrostome in the following topics:
- 
Flame Cells of Planaria and Nephridia of Worms- The ciliated tubules filter fluid from the body cavity and carry waste, including excess ions, through openings called nephrostomes.
- From the nephrostomes, excretion occurs through a pore called the nephridiopore.