_Remarks._--Howell (1920:230), without having examined the material, provisionally referred specimens from Requa and Crescent City, Del Norte County, California, to _Z. t. eureka_. I have studied this material and find the specimens to be intermediate between _Z. t. trinotatus_ and _Z. t. eureka_ in cranial characters (zygomatic breadth, interorbital width, and breadth of braincase), but nearer _Z. t. trinotatus_ in coloration (absence of ochraceous suffusion ventrally). They are here referred to _Z. t. trinotatus_. The zone of intergradation between _Z. t. trinotatus_ and _Z. t. eureka_ seems to extend from Requa, California, north to Gold Beach, Oregon, where other specimens intermediate between these two subspecies, have been obtained. These individuals are also referred to _Z. t. trinotatus_ on the basis of cranial features and color. _Specimens examined._--Total, 42, all from California, distributed as follows: _Humboldt Co._: Trinidad, 4 (SDM); Carsons Camp, Mad River, 3 (USBS); 3 mi. W Arcata, 5 (MVZ); _7-3/10 mi. E Bayside_, 1 (MVZ); _12 mi. S Korbel, on Maple Creek_, 2 (MVZ); _Falk_, 1 (MVZ); Carlotta, 1 (MVZ); _F. B. Summer Redwoods, S Eureka_, 1 (MVZ); _Maple Creek, 1 mi. W junction Mad River_, 12 (MVZ). _Mendocino County_: Mendocino City, 1 (MVZ); Albion River, 1/3 mi. E MacDonalds Ranch, 1 (MVZ); Russian Gulch State Park, 10 (MVZ). _Marginal records._--California: Trinidad; Russian Gulch State Park; Albion River, 1/3 mi. E MacDonalds Ranch; Mendocino City; Carlotta. =Zapus trinotatus montanus= Merriam _Zapus trinotatus montanus_ Merriam, Proc. Biol. Soc. Washington, 11:104, April 26, 1897; Bailey, N. Amer. Fauna, 55:234, August 29, 1936. _Zapus montanus_, Preble, N. Amer. Fauna, 15:28, August 8, 1899. _Type._--Female, adult, skin and skull; No. 79863, U. S. Nat. Mus., Biol. Surv. Coll.; Crater Lake, Klamath County, Oregon; obtained on August 19, 1896, by Edward A. Preble, original No. 1388. _Range._--From Crater Lake, Klamath County, Oregon, northward along the Cascade Range into Hood River County, Oregon. Zonal range: Transition and Canadian. _Description._--Size medium; back near Ochraceous-Buff with admixture of black hair, resulting in a grizzled, broad, dorsal band; sides lighter than back, from near Ochraceous-Buff to near Pinkish-Cinnamon, and lined with black hair; lateral line distinct; underparts usually pure white, sometimes with slight suffusion of ochraceous on lower throat and upper chest; tail bicolored, brown above and yellowish-white below; ears dark, sometimes flecked with ochraceous, edged with yellowish-white; feet grayish-white above; braincase relatively narrow; zygomata relatively short; condylobasal length short; mastoid region relatively narrow; palatal bridge short; auditory bullae large; frontal region inflated; pterygoid fossae relatively narrow.