my guess is calf.
I believe that only unlined shell shoes (like C&J Hahvahd) would show the Horween mark on the inside of the shell.If it is really shell is should say "Horween" inside. These pictures are not really good enough to say if it does, or not...
I concur here.The way the light is reflecting off the vamp in the picture I posted above seems to indicate a fair amount of creasing. (As a side note, I imagine when people said "wrinkles" what they meant was "creases." I doubt anybody actually thinks shell stays perfectly smooth.)