BIRDS OP NORTH ^ND MIDDLE AMERICA. 



359 



CORVUS CORAX PRINCIPALIS Ridgway. 



NORTHERN RAVEN. 



Admits (sexes alike). — Entire plumage deep glossy black; the wing- 

 coverts, secondaries, innermost primaries and tail glossed with violet 

 (the gloss on wings more purplish, sometimes inclining to bronze on 

 secondaries); primary-coverts and longer and outermost primaries 

 glossed with bluish or greenish; under parts glossed with blue or 

 greenish blue, becoming more violaceous on lanceolate feathers of 

 throat; shafts of primaries becoming whitish basally; feathers of neck, 

 etc., light gray basally; bill, legs, and feet black; iris deep brown. 



Adult male.— Length (skins), 622-675.5 (648.5); wing, 4:19.5^64 

 (438); tail, 235-259.5 (247); exposed culmen, 76.5-92 (81.5); depth of 

 bill at nostril, 26.5-31.5 (28.5); tarsus, 62-71 (68); middle toe, 43-54 

 (47.5); graduation of tail, 48-73.5 (54.5).« 



Adultfemale.— Length, (skins), 572-667 (624); wing, 413-440.5 (426); 

 tail, 229-246.5 (242); exposed culmen, 68-81.5 (76.6); depth of bill at 

 nostrils, 24-28 (26.5); tarsus, 63-73 (61.5); middle toe, 43-51 (46.5); 

 graduation of tail, 44.5-68.5 (50).* 



Arctic and Boreal Provinces of North America; south to eastern 

 British Provinces, portions of New England, and Atlantic coast of 



o Sixteen specimens. 



6 Fourteen specimens. 



Eastern and western specimens compare in average measurements as follows: 



Locality, 



Ten adult males from Greenland, Un- 

 gava, etc ' , 



Six adult males from Alaska 



Three adult males from I^ritish Colum- 

 bia -. . . : 



One adult male from mountains of 

 Pennsylvania 



Six adult females from Greenland, TJn- 

 gava, etc 



Kight adult females from Alaska 



Two adult females from British Colum- 

 bia 



Two adult females from Michigan and 

 mountains of Pennsylvania 



Wing, 



432,5 

 446.6 



437 

 432 



425 

 426 



423 

 409,5 



244,5 

 250 



262 

 241,5 



246, 5 

 240 



241,5 

 241,5 



Ex- 

 posed 

 culmen. 



.81 

 81,5 



79,5 

 79 



76,5 

 75,5 



73,5 

 74 



Depth 

 of bill 

 at nos- 

 trils. 



28,6 

 29 



26,6 

 26,7 



26 

 26 



Tarsus, 



67,5 

 69 



Middle 

 toe. 



46,5 

 48,5 



60,5 

 47,5 



46 

 45,5 



47 

 41 



Gradua- 

 tion of 

 tail. 



67 

 63,5 



58,5 

 58 



47,5 

 61,5 



71,6 

 43 



The specimens from British Columbia, Michigan, and Pennsylvania are not typical, 

 but incline more or less toward C. c. sinuatits. Their measurements are not included 

 in the extremes and averages given in the diagnosis, which are restricted to measure- 

 ments of specimens from Greenland, Ungava, Alaska, and other extreme northern 

 localities. 



