Intergradation with _streatori_ is complete as it is also with _invicta_ and _richardsonii_, in other words with each of the subspecies whose ranges meet that of _fallenda_. In color and in size the difference is least between _streatori_ and _fallenda_. As between _fallenda_ and _invicta_ the size is not greatly different and the intergradation in color is gradual. Between _fallenda_ and _richardsonii_ intergradation is somewhat different and to fully appreciate its nature we should remember that the color of _fallenda_ resembles that of the saturate coastal races, _streatori_, _anguinae_ and _olympica_ although the black tip of the tail is longer. In this latter feature and in several cranial details, as well as in greater degree of secondary sexual variation in size, _fallenda_ resembles _richardsonii_. Because the two differ more than do most subspecies of ermine whose ranges meet, some of the intergrades at first inspection appear to be widely different from either parent stock. For example, specimens from Alta Lake, British Columbia, may give this impression because the combination of large size and dark color suggests a kind of ermine different from either _fallenda_ or _richardsonii_. In no instance, however, has there been found in these intergrades any character other than those occurring in one or the other of the two parent races. Along the coast in the north part of the geographic range assigned to _fallenda_, some specimens nearly typical of _richardsonii_ have been taken so near to the place where fairly typical _fallenda_ was obtained that I have doubted whether there is intergradation in the usual fashion in this area; more specimens will have to be obtained from this coastal area to resolve the doubt one way or the other.