h. Mustela rixosa campestris, ♂ ad., same specimen shown in d.
i. Mustela rixosa eskimo, ♀ sad., 40059, Mus. Vert. Zoöl., Barrow, Alaska.
j. Mustela rixosa rixosa, ♀ ad., 12679, Nat. Mus. Canada, south of Shaunavon, Saskatchewan.
k. Mustela rixosa allegheniensis, ♀ ad., 33021, Field Mus. Nat. Hist., Stryker, Ohio.
l. Mustela rixosa allegheniensis, ♀ ad., same specimen shown in k.
m. Mustela rixosa eskimo, ♀ sad., same specimen shown in i.
n. Mustela rixosa rixosa, ♀ ad., same specimen shown in j.
o. Mustela rixosa campestris, ♂ ad., same specimen shown in d and h.
Plate 16. Photographs, retouched, of skulls in dorsal view of nine subspecies of Mustela frenata. Natural size.