This creature, known commonly as lumen, normally lives in the depths of the Marianas Trench in the Pacific Ocean near the tropical island of Guam. The organism provides its own light through a process of bioluminescence whose purpose is not yet fully understood. Lumen feeds off of the decomposing carcasses of sea creatures which drift to the bottom as well as krill.

Lumen is believed to be related to the rhizostomae order of sea jellies, since species of this order have neither tentacles nor other structures at the bell's edges. This organism incorporates a plexus of autonomic nerves and exhibits a curious peristaltic reflex to haptic stimuli.

There have been reported sightings of lumen which have grown to be up to three yards in diameter.

This lumen is contained here in a specially manufactured pressurized barometric capsule to simulate the extreme conditions under which the lumen normally live, over 1,000 times the atmospheric pressure at sea level.

This fine specimen was captured by Capt. Lysander Starr Jameson of the H.M.C.S. Yarmouth, who lead the submarine expedition to the depths of the Marianas Trench.

 
A Generous Bequest of Mme. Letitia Napier Rathmore