There's also a more recent discrepancy between novels' portrayals of the Rigellian (or Rigelian) species mentioned in "Journey to Babel," the one with similar anatomy to the Vulcans. Catalyst of Sorrows claims that they have Vulcanoid internal anatomy but all look human externally (presumably on the assumption that Hengist from "Wolf in the Fold" was one of them), but David Mack's novels describe Safranski, the Rigelian in President Bacco's administration, as looking like a Vulcan. (I don't remember whether Articles of the Federation claims this as well.)
According to Memory Alpha and Beta, the Rigel Colonies encompass a variety of humanoid species, all of whom seem to be referred to as Rigellians (or Rigelians), including the Chelons. At this point, I think "Rigellian" is more a descriptor of origin than of species, sort of like saying someone is a "Texan" doesn't tell you anything about his or her ethnicity.