(holotype and paratypes), _A. p. sowerbyi_ differs
in most of the same ways in which it does from _peninsulae_ as well as
in having more shallow zygomatic notches, narrower zygomatic plates and
smaller, more slender, upper incisors. From _Apodemus peninsulae
nigritalus_ of the Altai Mountains of Siberia (holotype and paratypes),
_A. p. sowerbyi_ differs in: Smaller size, both external and cranial;
paler dorsal coloration; less convex cranial outline in lateral view;
smaller auditory bullae.

_Remarks._--_Apodemus peninsulae sowerbyi_ is named in honor of the late
Arthur de Carle Sowerby whose collections of mammals from North China
and Manchuria have added so much to our meager knowledge of that part of
the world.

Four specimens from Hsin-lung-shan, 65 mi. NE Peking, here assigned to
_sowerbyi_, are darker dorsally than mice from farther to the west and
in this respect may show approach to _A. p. praetor_. In all other
features, however, they closely resemble the new subspecies.

All of the specimens of _sowerbyi_ available to me are from altitudes of
3000 feet or higher. At lower elevations in North China, destruction of
wooded habitats owing to intense land-use practices has probably
restricted the distribution of _sowerbyi_ primarily to hilly and
mountainous areas where brushy, scrub and forest habitats still prevail.

_Specimens examined._--Thirty-three, all from North China, as
follows: JEHOL: Hsin-lung-shan, 65 mi. NE Peking, 3000 ft., 4.
KANSU: 15 mi. S Lanchow, 7400 ft., 1. SHANSI: Chiao-cheng-shan, 90
mi. W Taiyuan, 7000-8000 ft., 4; 30 mi. W Kuei-hau-cheng, 7000 ft.,
5; Lung-wang-shan, 20 mi. E Taiyuan, 4000 ft., 10; 18 mi. W
Taiyuan, 5000 ft., 1; 50 mi. NW Taiyuan, 5500 ft., 4. SHENSI: 12
mi. S Yenan, 4000 ft., 4.

_Apodemus peninsulae_, then, is known or suspected to occur over much of
southeastern Siberia, Manchuria, Korea and North China. The western
limits of its geographic range are unknown. Over this vast area only
four subspecies, one newly named, can be ascribed with certainty to
_peninsulae_ whereas only two other kinds, _giliacus_ of Thomas from
Sakhalin and _rufulus_ of Dukelsky from extreme southeastern Siberia are
probably conspecific with it, the latter possibly a synonym of
_praetor_. These considerations underscore the preliminary nature of the
present paper. The mammalian fauna of northeastern Asia is scarcely
better known today than was that of North