The column is in the central portion of the flower.
The callus is on the lip of the flower closest to the column.
Here is a closeup of the flower parts I'm talking about. It isn't the best angle to tell what's going on, but you get the point...
I'll try and look for a better one, a bit later.
http://www.orchidspecies.com/orphotd...opspapilio.jpg
Psychopsis papilio is a species, btw. Be aware that the species name is always in lower case!
Psychopsis Mendenhall is a hybrid. Psychopsis Kalihi is also a hybrid, as is Psychopsis Mariposa. Be aware of the capitalization of the hybrid names - they are always denoted properly in such a way.
To avoid confusion, I highly recommend observing the use of the capitalization of hybrid names, and denoting species names starting with lower case letters.