Har has stated it multiple times, but I can't remember clearly. I believe the female is the start of the name of the hybrid, therefore Atemoya would be Ate (sugar apple) pollinated with the pollen of a cherimoya. I do believe in common usage however that any hybrid of the the two would be referred two as Atemoya.
If I have remembered the naming convention properly the cherilata is a cherimoya pollinated by a reticulata. I do believe it was a reticulata thread where Har divulged the naming convention.