Eureka!
I got it. Thanks a million. To recap, in addition to the excellent tips, I downloaded the drivers from Epson, renamed them from *.sea files to *.app files per the Epson support people, and then I had some additional installing to do apparently. It works!
Now I have a questions born of simply inability to understand the Mac way of doing things. I frequently need to scan black and white images, and make minor changes. With PC, I'd used Paint to alter bitmap images. Mac has neither Paint nor bitmaps. What would I use in Mac instead of bitmap images and paint?