Most of these characters have to do with degree of inflation of the bullae.
The bullae are less inflated even than in the mink, subgenus Lutreola.
The bullae are, therefore, relative to the basilar length, longer in primulina.
Otherwise, the bullae agree with those of the type specimen.
Specimens from five miles south of Cotopaxi also have the bullae more flattened ventrally.