Nomenclature for lophs (left) and cusps (right) of typical low-crowned notoungulate upper (above) and lower (below) teeth. Figures are adapted from Cifelli (1993).  Anterior is to the right for all diagrams; labial (toward the lips) is toward the top of the diagram in the upper molars and toward the bottom in the lower molars.  The crochet can be seen as a loph running anterolabially from the middle of the metaloph in the upper molars (colored in red).  Note that the names of most cusps end in "cone" for upper teeth and "conid" for lower teeth; similarly, upper teeth have "lophs" while lower teeth have "lophids."