j 1915.] 



MAEMOTA FLAVIVENTKIS GROUP. 



51 



buff (the underfur ochraceous-buff ) ; feet hazel or tawny; tail above, 

 mixed hazel and chestnut-brown; beneath, blackish brown; iinder- 

 parts ochraceous-buff (bases of hairs brownish) varied with tawny 

 along sides ; rump and buttocks warm buff. Dark 'phase (specimen 

 from Boulder County, Colo., altitude, 8,000 feet) : Underfur cinnamon- 

 buff becoming dark cinnamon on hinder back; entire body extensively 

 mixed with dark chestnut-brown hairs, sparingly tipped on back 

 with light buff; feet blackish brown shaded with tawny; light face- 

 markings reduced. 



Skull. — ^Very similar to that of nosofhora, but averaging relatively 

 narrower, especially rostrum and interorbital region; bullae smaller. 



Measurements. — ^Adult male:^ Total length, 600-650 (average 

 623); tail vertebrae, 182-220 (200); hind foot, 86-90 (88). Adult 

 female: 2 552-618 (579); 137-192 (171); 78-85 (81). Skull: Adult 

 male:^ Condylo-basal length, 86-92.5 (88.3); palatal length, 48.4- 

 51.1 (49.5); postpalatal length, 33.5-36.5 (35.2); length of nasals, 

 36-41 (38.4); zygomatic breadth, 55.7-60 (57.9); breadth across 

 mastoids, 39-43.4 (41.5); least interorbital breadth, 17.3-21.8 (19.2); 

 breadth of rostrum, 18.9-20.8 (19.6); maxillary tooth row, 19.9-21.4 

 (20.5). Adult female:* Condylo-basal length, 78.3-85 (81.4); pal- 

 atal length, 43.7-47.6 (45.7); postpalatal length, 30-33.3 (31.5); 

 length of nasals, 32.5-35 (33.7) ; zygomatic breadth, 51.7-54.9 (53.3) ; 

 breadth across mastoids, 37.5-40.5 (38.6) ; least interorbital breadth, 

 16.4-17.8 (16.9); breadth of rostrum, 17.3-18.3 (17.8); maxillary 

 tooth row, 19.3-21;4 (20.2). 



Remarks, — In studying the marmots of this and related races in 

 Colorado several puzzling problems have been encountered, the ma- 

 terial at present available being insufficient satisfactorily to work out 

 the characters and exact relationships of the forms. The specimens 

 exhibit considerable individual variation, and, in addition to the dark 

 phase already described, a light phase, characterized by less yellow- 

 ish underparts and white tips to the hairs above, occurs in the same 

 localities with the normal phase. Specimens in this light phase are 

 known from Meeker, North Park, and Boulder County (altitude 

 10,300 feet). They rather closely resemble engeThardti externally, 

 except that the underfur and feet are paler: the skulls, however, are 

 typical of luteola. 



The series from Laramie Mountains, Wyo., is intermediate between 

 luteola and dacota, the pelage averaging redder and the skuUs 

 relatively shorter and broader than in typical luteola. Most of 

 this series have large ochraceous-buff face markings. The series 

 from Sulphur Springs, Colo., shows intergradation with warreni, the 



1 Three specimens from southern Wyoming and northern Colorado. 



2 Six specimens from northern Colorado. 



3 Four specimens from Laramie and Medicine Bow Motiatains, Wyo., and Mount Lincoln, Colo. 

 * Five specimens from northern Colorado. 



