ganglion lies beside the nerve ring in the head, just anterior of the retrovesicular ganglion. It contains about 20 interneuron and motorneuron cell bodies that all send their neuronal processes into the ring. The cell bodies are divided into two groups by the intrusion of the excretory duct and canal. The cells are bounded by a basal lamina which physically separates them from the lateral ganglion even though they are adjacent to one another.