I agree with Gert - almost.  I believe Hinnites is actually derived from the
masculine Latin noun "hinnus", meaning mule.  The suffix "-ites" added to a
noun root means "having the nature of", or more loosely translated,
"resembling".  Therefore, Hinnites literally means "having the nature of a
mule", or "resembling a mule".  Just what Defrance had in mind when he named
this genus in 1821 is not clear.  Perhaps it was a reference to the animal's
"stubborn refusal to move" when trying to get it loose from the substrate on
which it grows.  Or perhaps "mule" was used to indicate something large and
bulky, the way "dog" was used to indicate something very common and
ordinary.  Curiously, Wood actually named this genus Hinnus - mule, but he
was too late.  Defrance had named it Hinnites five years earlier.  Odd
though, that each of them though this mollusk was in some way "mule-like".

Paul M.