From topotypes of _C. g. phaeus_, _C. g. stikinensis_ differs as follows: dorsal stripe and sides darker; auditory bullae less inflated; cheek-teeth narrower; skull smaller in most measurements taken (see table 1). From topotypes of _C. g. solus_, _C. g. stikinensis_ differs as follows: dorsal stripe lighter (more tawny underwash); ventral wash of buffy much paler (especially noticeable around mouth and on throat); zygomatic and lambdoidal breadths greater; skull deeper; auditory bullae more inflated; cheek-teeth slightly heavier. TABLE 1. _External and cranial measurements of Clethrionomys._ N | | | | | | | | | | | u | | | | | | | | | | | m | | | | | | | | | | L | b | | | | | | | | | | e | e | | | | | | | | | | n | r s | | | | | | | | | | g | e | | | | | | | | | | t | o x | | | | | | | | | | h | f | | | | C | | | | | | | o | | | | o | | | | | | o | i r | | | | n | | | | | | f | n | | | | d | | L | | A | B | | d s | | | | y | Z | a | | l | r | i | i p | | | | l | y | m | L | v | e | n | v e | | | | o | g | b | e | e u| a | c | H i c | | | | b | o | d | n | o p| d | i | e d i | | | | a | m | o | g | l p| t | s | i u m | T | | | s | a | i | t | a e| h | i | g a e | o | | | i | t | d | h | r r| | v | h l n | t | | | l | i | a | | | o | e | t s | a | | H | a | c | l | o | l t| f | | m | l | | i | r | | | f | e o| | f | o o e | | | n | | b | b | | n o| r | o | f f a | l | | d | l | r | r | n | g t| o | r | s | e | | | e | e | e | a | t h| s | a | s e u | n | T | f | n | a | a | s | h | t | m | k a r | g | a | o | g | d | d | a | r| r | i | u c e | t | i | o | t | t | t | l | o o| u | n | l h d | h | l | t | h | h | h | s | f w| m | a | l _Clethrionomys gapperi solus_, Loring