For further research on nuances of this image, try looking
for articles and book refs. in something like the Art Index (at
most libraries, even non academic ones I believe) or the BHA (Bibl. of
the History of Art), or if you have an academic library handy that
subscribes to the Index of Christian Art, you can just search for
"hell's mouth" or variations and get a list of specific
monuments/items with descriptions..
Leah Rutchick
