Vase Symbol with : Semi Vitreous Next line: Edwin M Knowles Next line: China Co. Next line: Made in U.S.A. Next line: 46-8

I found these in a box with some other older plates I got at an auction so I can’t ask anyone because I’m not sure who they belonged to or if they are still living. I’m just trying to find out the history so I can put the info with the plates and make a decision on keeping or selling them.

Thank you so much for any help!!