1915.] 



MAEMOTA CALIGATA GEOUP. 



63 



interorbital breadth, 22.2; breadth of rostrum, 20.5; maxillary tooth 

 row, 21.8. 



Remarks. — -This race is a small form of caligata, confined to Mon- 

 tague Island, and differing from the typical race in size and skull 

 characters. On Hinchinbrook Island, separated from Montague 

 Island by only a narrow channel, the typical form is found. 



Specimens examined. — Seven, from type locality.^ 



MARMOTA CALIGATA OXYTONA Hollister. 



RoBSON Hoary Marmot. 



(PI. Ill, fig. 1; PI. IV, fig. 3; PI. IX, fig. 2; PI. X, fig. 4.) 



Marmota sihila Hollister, Smiths. Misc. Coll., Vol. 56, No. 35, 1912, p. 1. (Not Arctomys 

 sibUa Wolf.) 



Marmota oxytona HolHster, Science, N. S., XXXIX, No. 998, Feb. 13, 1914, p. 251 

 (new name for Marmota sihila Hollister). 



Type locality. — ^Head of Moose Pass branch of Smoky Eiver, 

 Alberta (altitude, 7,200 feet). 



Distril)ution.~ln.teiT\OY of northern British Columbia, southwestern 

 Mackenzie ( ?), and southern Yukon, from Teslin Lake andLiard River 

 south to Barkerville, British Columbia, and the Mount Robson region, 

 British Columbia and Alberta. 



Characters. — Colors much blacker and tail darker than in caligata; 

 skull larger and relatively narrower; males but little larger than 

 females. 



Color. — ^Upperparts as in caligata, but more extensively tipped with 

 black, the underfur fuscous, shading to deep mouse gray or fuscous- 

 black; hinder back dark cinnamon-buff, tinged with hazel and 

 heavily mixed with black; top of head black with rather small white 

 patches; cheeks ochraceous-cinnamon, varying to buffy white; tail 

 above, dark cinnamon-buff mixed mth bay, the bases of the hairs 

 chestnut-brown or blackish brown; beneath, blackish brown, tinged 

 with bay; underparts soiled whitish mixed with dull cinnamon, the 

 bases of the hairs blackish brown. 



SlcuU. — Much longer and relatively narrower than that of caligata, 

 with long rostrum; zygomata less widely expanded posteriorly; zygo- 

 matic arch longer and distance from squamosal arm to tip of post- 

 orbital process greater; nasals terminating on a line mth ends of 

 premaxiUae or sHghtly posterior; interpterygoid fossa relatively 

 narrower. 



Measurements. — Adult male Total length, 720-775 (average, 747); 

 tail vertebrae, 210-235 (221); hind foot, 100-110 (105.6). Adult 

 female:' 720-740 (730); 210; 95-105 (100). Slull: Adult male:^ 



1 Five in collection Mus. Vert. Zool., Univ. of California. 



2 Five specimens from British Columbia (Mount Robson to Thudade Lake). 



3 Two specimens from Sustut Mountains, British Columbia; and head of Smoky River, Alberta. 

 * Seven specimens from northern British Columbia. 



