I agree intergrade would be a better term for a cross of BG X CNBG i.e. two subspecies, varieties, or forms, whereas hybrid is a cross of two different species . Here is what the reptile 'people' think which probably agrees with most biologists.
http://www.hybridherps.com/forum/index.php?topic=60.0

Last edited by Bill Cody; 12/23/15 03:44 PM.
aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management