http://www.projecthalo.com/aura#Statocyst

A type of gravity sensor that functions in equilibrium, found in many invertebrates. It consists of a mineralized concretion in a fluid-filled sac lined with hair cells. As the animal moves, different hair cells are stimulated, providing information about the animal's orientation with respect to gravity.

Statocyst

Statocyst

http://www.projecthalo.com/aura#Transverse-Tubule

http://www.projecthalo.com/aura#Z-Line-Filament

http://www.projecthalo.com/aura#Synaptic-Terminal

http://www.projecthalo.com/aura#Animal-Cell-Structure