Ok here's a hint - Look at the main distinguishing feature that separates it from the other species of Citharacanthus (pics on the last page) then have a read through of this

OK I see. So basically you are saying that they separated this species from the shape of the spermathecae but the specimen they checked doesn't even have any?

Yep. The "spermathecae" that they show are quite clearly male accessory organs. The lack of uterus externus and bursa copulatrix as well as the fact there is a gonopore clearly visible between the structures is a big give away.
Given the location of Tuxtla Gutierrez, Chiappas and the fact they have put it in the livingstoni group of Citharacanthus, I would hazard a guess that it is quite possibly not even a Citharacanthus but a sub adult male Brachypelma vagans.

Very interesting. Sometimes these taxonomists make me think...