Millei—Tiro Neir Mvrivc Rodevts from Kadcrii 
primanus for the eusteni form.* Ifotli caraco und socer are dLstiii- 
guishiil)le from true norvegicus l)y less luirsli fur, more liairy tail (the 
amudations mostly concealed, and the color of dorsal surfaces of tail 
noticeably darker than that of body), shorter hind foot, and by the 
smaller skull with more abruptly constricted interorbital region and more 
nearly parallel ridges on braincase, the least distance between these ridges 
at interparietals tending to be equal to or less than that between ])ost- 
orbital angles, while in true norvegicus it is usually (though not invariably) 
greater. 
* .\iin. Mus. Zool. Acad. St. I'Ctorsbourg, Vol. 17, (UM2). p. 401, lOK!. 
