nephridium: The renal organ of mollusks, corresponding to kidneys in vertebrates.
D, Lateral view showing the actual relation of the glandular and non-glandular sacs of the nephridium.
The figure is given to shew the peritoneal funnel of the nephridium.
D, Optical section of a branch of the nephridium of Nephthys scolopendroides.
Portion of nephridium of the hindermost leg of Peripatus capensis, seen in longitudinal and vertical section.
Externally, the nephridium opens by a vesicle, as in many Oligochaetes whose lumen is intercellular.
There are thus substantial reasons for believing that the nephridium grows backwards from a funnel as does the coelomoduct.
Close to the point where the vesicle joins the coiled section of the nephridium the former has a peculiar nick or bend in it.
Such a nephridium from the ninth pair of legs is represented in fig. 28.
nephridium ne·phrid·i·um (nə-frĭd'ē-əm)
n. pl. ne·phrid·i·a (-ē-ə)
The embryonic excretory organ from which the kidney develops.