I am no expert but since there have been no other responses all day I will throw my two cents in. As far as I know Ultra is a type of Hypomelanism where an Ultra is close to a hypo in appearance and ultramel is a cross between the Ultra and Amel since Ultra is allelic to Amel. When combined with Anery that is where it seems things get hard to tell. A "very" loos rule of thumb is that an Ultra Anery is darker in appearance compared to an Ultramel Anery. In both instances they look similar to ghosts. But looking at examples from several breeders, that does not always seem to fit the bill. VMSHerp is doing some great work with the Ultra gene and has many examples on
www.VMSHerp.com and Done Sodersberg has some great examples too at
www.cornsnakes.net. Several great looking Ultramel Anerys may also be seen at
http://iansvivarium.com/morphguide/ultramelanery/. Most breeders will end up telling you though that half the time unless breeding trials have proven both parents are true Ultra Anerys then the offspring are usually labeled as Ultra/Ultramel Anerys because it is too hard to identify some times. So my question to you, was this a curious question or have you seen some snakes you want and are looking for identifying advise? Usually the more back story you can give to catch peoples attention will drive more answers.