I just had to rescue this plate from the 50c pile at Goodwill. But I have not been able to find out much about it from the usually-helpful archives of Google. Maybe someone out there in internet land will know more?
The back is marked "Fine Staffordshire Ware by E[?]ce National New York NY. Made in England. Underglaze detergent proof".
Edited to add: It had the name "Denver Museum of Natural History" from 1948 to 2000.