As in other Isothrix, there is no neoflexus on any cheektooth. On the [M.sup.1], the hypoflexus is large and short, sharply square against the protocone and hypocone.
* LUM, length of upper molariform toothrow -- maximum length from the anterior edge of alveolus of first cheektooth to the posterior edge of the alveolus of last molar.