Which stylus is correct for a Shellac LP

... and that would be?!

OMG.  I have a stylus for my 78s, and I have a stylus for my LPs (33 1/3).  The question is: are the grooves on the *shellac LPs* wide (like they are on 78s) or narrow (like they are on LPs). Did the recording process affect the grooves (utilize or create narrow grooves) when they made shellac LPs?    

"The eye" is relative, (or at least mine is no longer that objective), but I take the reasonable explanations offered - thank you!  I only asked in the first place because I was always taught the rule of thumb: Stiff = Shellac and 'Bendy' = Vinyl.  I actually have a quite a few stiff LPs.  Do I now I have to worry about using a mono stylus for those playbacks instead of the 2 channel stylus I normally use? 

Not a "purist" - (I assume you mean a mono cartridge, etc., for mono LPs) - although I probably would be if I could afford to be.  I just want to protect the equipment and platters, and it sounds like I can proceed with what I have.  Thanks, again.  Micro-groovy!