This name is a synonym of Fissidens dubius P. Beauv..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 35180888) with original publication details: Proc. Amer. Acad. Arts 14: 137 1879.
This name was in version 1 of The Plant List, record tro-35180888, and has not been changed.