With all the new varieties it gets confusing.The foliage and flowers look the same.
I usually go to Karchesky's website to look up cannas. I think they have the most available information. I've included a link below and they have these two listed as different ones. The red stripe has a very small red bloom. On my monitor the bloom on the Scarlet's Rib looks a little more melon colored.
Here is a link that might be useful: Karchesky Cannas