Looks like a defective planchet to me. Got a bit of lamination on the right side of it on the dated side, near the 'N'. May have been cut through a fissure or a blowhole. I have a 1876 Canadian cent with a blowhole that looks a bit similar to it.
Are you sure? To me it looks like it could be more damage from the cut. Maybe the images could be clearer? IDK.
Although the photos are poor, I would go for a planchet flaw - I have handled many similar, as the alloys were poorly mixed in this period. To British collectors, this type of flaw is considered a defect rather than something to attach a premium to.
I hope I don't come across that way as my knowledge is limited, but I try giving the best answer and advice based upon my experience. I'm only human and make mistakes every day. LOL
Oh no no no, I'm saying you're much better than me at this! Didn't try to make you think that I was being rude to you!