See also: Lamellar Body = Pineal Gland.
Pineal Eye Information (Goog)
New Perspectives ... Origin of Brain (PubMed)
"The anterior nerve cord of a young amphioxus larva in dorsal view, based on serial electron microscope reconstruction data"
FE = Frontal Eye
BO = Balance Organ
LB = Lamellar Body
PMC = Primary Motor Center
Basic features of the ancestral chordate brain (Wiki)
"Amphioxus has direct pathways for activating its locomotory circuits in response to mechanical stimuli via epithelial sensory cells, but this response is evidently modulated by inputs from diverse sensory-type cells located in the putative hypothalamic homolog, and from the lamellar body, the pineal homolog."
Ruiz, M.S., and Anadón, R. 1991b.
The fine structure of lamellate cells in the brain of amphioxus (Branchiostoma lanceolatum, Cephalochordata).
Cell Tissue Res. 263: 597–600.