The type specimens of _Apodemus praetor_ Miller (type from Sungari River, 60 mi. SW Kirin, Manchuria) and _Apodemus nigritalus_ Hollister (type from Tapucha, Altai Mountains, Siberia) agree with _peninsulae_ as concerns the above characters and differ from it only in minor external and cranial features. They are, therefore, here considered as subspecies of the latter. Ellerman (1949:32) and Ellerman and Morrison-Scott (1951:567) regarded _nigritalus_, like _peninsulae_, as a subspecies of _flavicollis_. The subspecies _praetor_, on the other hand, has generally been regarded as a synonym of _peninsulae_ by recent authors. Howell (1929:58) noted that the holotype was, "... a phenomenally large specimen such as is encountered occasionally in almost all groups of rodents." He ascribed the color differences noted by Miller to "seasonal" variation. The holotype of _praetor_ is undeniably larger than the other adult specimens listed in the original description. These paratypes and other specimens of _praetor_ available to me are approximately the same size externally and average only slightly larger cranially than specimens of _peninsulae_ from central and southern Korea. However, the dorsal coloration of _praetor_ is somewhat darker and duller than that of _peninsulae_, especially in summer pelage when _praetor_ lacks the conspicuous bright ochraceous tinge of the Korean specimens. In addition, _praetor_ has broader zygomatic plates with correspondingly deeper zygomatic notches and the color on the face of the upper incisors averages much more orange than in _peninsulae_. In the north then, wood mice range from Korea and Manchuria westward at least as far as the Altai Mountains. For mice from the intervening Siberian areas Russian workers have used the name _major_ which, as noted above, is unavailable. The exact relationships of the mice of these areas to previously named subspecies is unknown to me and I have not seen specimens of "_Mus (Alsomys) major rufulus_" of Dukelsky, 1928, the type locality of which is 75 versts (approximately 50 miles) SE Vladivostok, Siberia. It appears to be of the same species as _peninsulae_ and judging from the original description it closely resembles _praetor_. Neither have I seen specimens of the Sakhalin Island mouse, _giliacus_, which Ellerman (1949:32) regards as a subspecies of _Apodemus sylvaticus_. I feel reasonably sure, however, that it will prove to be a subspecies of _peninsulae_. In the original description _giliacus_ was referred to as, "Most closely allied to the Korean subspecies..." (Thomas, 1907:411).