Thus, in the Phyllopoda, the antennal gland develops early and is functional during a great part of the larval life, but it ultimately atrophies, and in the adult (as in most Entomostraca) the maxillary gland is the functional excretory organ.
In the Decapoda, where the antennal gland alone is well-developed in the adult, the maxillary gland sometimes precedes it in the larva.
In the Decapoda the antennal gland is largely developed and is known as the " green gland."
The centres for the antennal nerves form ganglionic swellings on the oesophageal connectives.
In the higher forms, as already mentioned, the antennal ganglia have become shifted forwards and coalesced with the brain.