The Collaborative International Dictionary of English v.0.48:

Bathybius \Ba*thyb"i*us\, n. [NL., fr. Gr. baqy`s deep + bi`os
   life] (Zool.)
   A name given by Prof. Huxley to a gelatinous substance found
   in mud dredged from the Atlantic and preserved in alcohol. He
   supposed that it was free living protoplasm, covering a large
   part of the ocean bed. It is now known that the substance is
   of chemical, not of organic, origin.
   [1913 Webster]