oph·i·cleide 
(ŏfĭ-klīd′)
(ŏfĭ-klīd′)n.
A keyed brass instrument of the bugle family with a baritone range that was the structural precursor of the bass saxophone and was replaced by the tuba in orchestras.
[French : Greek ophis, snake (from its resemblance to the serpent, a musical instrument) + Greek klēis, klēid-, key.]