Both Tok'ra and Goa'uld have evolved from a primitive form found in the episode The First Ones. This primitive form is simply referred to as "Primitive Goa'uld". The species itself is not named.
Goa'uld means "god(s)", whereas Tok'ra means "against Ra"(the main antagonist of the film). It is important to note too, that Tok'ra are split from the Goa'uld themselves.
So to answer your question, the species itself is never named, other than the colloquial terms that are used to refer to the majority of the species (the Goa'uld). However though it is apparent that neither Goa'uld nor Tok'ra satisfactorily represents the name for the entire species, Goa'uld for all intents and purposes is the name of the species.