Thanks everyone for the responses.
My own previous research confirmed a lot of what you shared here although there didn't seem to be a clear cut specific reference right across the board in the frog hobbyist community unless you are dealing with certain specific experienced breeders. It seemed that some people use it depending on what their own preferences are rather than any scientific related zoological cataloging. The confusion stems from which of the two terms people prefer to use it seems although usage should be based off the locale factor at the very least as already stated. I also noticed that a larger majority of references to M.E. refer to specimens typically witout the helix like pattern on the back while M.B. almost always seems to refer to the helix patterned specimens. Then there is the matter of slight color differences/morphs, ie brown - orange, bronze, yellowish brown, etc.
I have two WC specimens that I rescued from a local pet store a little under a year ago that they had cataloged as M.E. After pushing them to provide information about the specimens I found out that they were imported by a company called Midori who I attempted to contact without any successful responses. Afterwards I was advised that the store staff was advised that these specimens were wild caught but Midori would not provide the locale from which they were obtained.
I have a trio of M.B. from Understory that I have kept separate from the Midori pair until I can clearly ascertain if they are the same species or different morphs of the same species or what have you. To the naked eye they appear the same although one set is slightly more "bronze" for lack of a better word and has a more obvious helix pattern where as the other has a weaker / broken helix pattern. But this doesn't prove anything as it is my understanding that siblings in the same clutch can sometimes have the odd subtle recessive characteristic show up that is different from the remaining kin. To some this may not be a huge deal but if I am successful in establishing a breeding colony and was to pass along the offspring to others I would want to provide accurate info as much as was possible as to the actual species designation.