Extracting plates from Google books

Mediterranean Ceramics posts Brief Thoughts on EPUB Books at Google

...
Once you've downloaded that file, it's easy to unpack. I'm a Mac/Linux user. If you are too, and you like the command line, 'unzip Catalogue_of_Arretine_pottery.epub' will do the trick. Otherwise, change the extension to ".zip" and double-click on the file. I'm sure something similar will work in Windows.

Once unpacked, you have two directories, 'OEBPS' and 'META-INF'. The first is the one with all the goodies in it. Open 'OEBPS/images' and you'll see the plates from the book. Those files aren't hi-res, but better than nothing.