Yes. "A" through "H" stamps exist and were intentionally non-denominated as the stamps had to go to press before the new postage rates were announced. At first, the non-denominated stamps were only good for domestic mail only but later was good for international mail as well, as non-denominated stamps became acceptable.
Here's a "cheat sheet" from the USPS identifying the non-denominated stamps (and in several cases, denominated stamps of the same design were created afterwards):
http://pe.usps.com/cpim/ftp/manuals...00/q604a.pdfThe text stamp shown in your scan, is arguably one of the ugliest issues ever in the US. It equals 4-cents in value, though, and is still valid today for that amount. It is Scott #2521.