1915.] 



MAE M OTA CALIGATA GROUP. 



65 



Type locality. — Gold Range, British Columbia. 



BistrihutioTi . — Gold and vSelkirk Ranges, Britisii Columbia, and 

 probably main range of the Rocky Mountains in Alberta from Banff 

 to Hemy House ; exact limits unknown. 



Characters. — Similar in color to oxytona. but averaging a httle 

 whiter; skull similar to that of caligata. 



Color. — Upperparts much as in oxytona, but averaging whiter 

 (some specimens almost as pale as caligata, but tail darker) ; under- 

 fur fuscous, shading to clove brown; fore back white, hinder back 

 cinnamon-buff, more or less overlaid with black: sides of face cinna- 

 mon mixed with white; feet blackish bro\\Ti, the hind feet grizzled 

 with, cirmamon; tail above, deep cinnamon (sometimes mixed with 

 hazel) bordered ^vith blackish brown, the bases of the hairs hght 

 chestnut-bro^m; beneath, blackish brown or dark chestnut-brown; 

 underparts soiled whitish mixed mth dull cinnamon. 



Shull. — Similar to that of caligata, but averaging shghtly larger, 

 with narrower rostrum and postorbital constriction; nasals shorter, 

 usually terminating httle if any posterior to ends of premaxiUae. Com- 

 pared with oxytona: Decidedly shorter and relatively broader; brain- 

 case less elongated and distance from tip of postorbital process to 

 squamosal arm of zygoma much less. 



Measurements. — xldult male : ^ Total length, 670-754 (average, 694) ; 

 tail vertebrae, 202-218 (212); hindfoot, 91-106 (98). Adult female:^ 

 659-735 (695); 202-224 (212); 93-103 (94). Shull: Adult male: ^ 

 Condylo-basal length, 95-100 (97.7); palatal length, 53.4-57.4 (55.5); 

 postpalatal length, 37-38.1 (37.8); length of nasals, 37-40.5 (38.9); 

 zygomatic breadth, 64.8-67 (66.2); breadth across mastoids, 45.2-46 

 (45.6); least interorbital breadth, 24.9-27 (25.7); breadth of rostrum, 

 23-25.2 (24.2) ; maxiUary tooth row, 21.9-22.7 (22.4). Adult female : ^ 

 Condylo-basal length, 94.4-97.6 (96.4); palatal length, 53.5-55.3 

 (54.5); postpalatal length, 36-38.7 (37.3); length of nasals, 38-40.3 

 (39); zygomatic breadth, 62.2-66.3 (64.4); breadth across mastoids, 

 42.2-45.5 (43.7); least interorbital breadth, 21.9-24.9 (23.7); breadth 

 of rostrum, 21-23.3 (21.9); maxillary tooth row, 21.4-22.4 (22). 



Remarlcs. — This race apparently has a rather limited distribution, 

 but its characters are well marked. It is not in any way inter- 

 mediate between oxytona and nivai^, as might be expected from its 

 geographic position, for, while it agrees with the former in color, its 

 skuU is much smaller than in either and more nearly resembles that 

 of caligata. It is very much darker in color than nivaria, the differ- 

 ences being especially noticeable in the young. 



1 Four specimens from Selkirk Range, British Columbia. 



2 Six specimens from same localities. 



3 Three specimens from Glacier and Nelson, British Columbia. 

 * Five specimens from same localities. 



I591&S°— 15— 5 



