Continental Divide

Is Panama part of North America?  Is it part of South America or Central America?  Does “Central America” even exist?  Is Panama west of the Canal in North America and east of the canal in South America?  People like to debate it, but I personally don't really care which is "right".  Though, I did find some evidence to suggest that some obscure map making company, that sells their maps in a Panamanian dollar store (Todo a Dollar), doesn't even think it's worth noting.  Sold as a packaged set, these two maps neglect to mention those seven countries sandwiched in between Mexico and Colombia:   

I'm not sure what they're trying to say, but I’m not sure I like it...  ;)