excretory gland

Many arachnids have only one or the other type of excretory gland, although several do have both.

The saccate metanephridia are excretory glands which function similarly to the metanephridia.

The organs of Bojanus or Bojanus organs are excretory glands that serve the function of kidneys in some of the Mollusca.

The excretory glands of arachnids include up to four pairs of coxal glands along the side of the prosoma, and one or two pairs of Malpighian tubules, emptying into the gut.