= NGC 1278 = GC 675 = Big 375 = d'Arrest 56. Bigourdan has this in
his fourth list of new nebulae (= Big 375), but in his final publication, he
includes the measurements for it under the number NGC 1278. He has this note
for the object: "This nebula has been listed under the number GC 674 by Lord
Rosse, and in the NGC. It is this that led me to at first suppose that it was
a new nebula."
Thus, it is clear that Bigourdan was misled by the typo (or misidentification?)
in Lord Rosse's observations and in the NGC. Just as clearly, he found the
problem during preparation for publication of his data. The positions for NGC
1278 and IC 1907 are close enough to confirm the identity.