You know, I don't think it likely to be ventrata, as what I have seen from the Midwest, the ventrata are actually labled "N. alata." However, the others are usually labled N. Coccinea or N. Miranda.
SRduggins may be onto something with the Gubler thing, as I "think" from their site they used to say "Nepenthes Hybrid".
I just checked and you don't seem to have access to specific info, but they do say:
"Nepenthes is a jungle vine found growing in the wild in Indonesia and Madagascar. There are approximately twenty species that still exist."
Wow! Look at all the extictions that have occured recently! Last I knew it was around 80 species, lol!