BIRDS OF NORTH AND MIDDLE AMERICA. 257 



ings). Eggs 3-8, light hliiish or greenish (nioiv rarely whitish) more 

 or less thickly speckled with brown or olive. 



Riuuji'. — Nearly cosmopolitan (absent ^only in Lesser Antill(>s, Cen- 

 tral and South America. Madagascar, New Zealand, and part of 

 Polynesia). 



Three of the five West Indian species ((". j(iiii<(lcen.H/s, ^J. naslcus^ 

 and C '. leucofj/utjj/ialiis) seem very distinct in their exposed nostrils, 

 semierect nasal plumes, large naked postocular space, and moi-c com- 

 pressed bill, but the other two {O. solitarius and C. minufn.s) are 

 intermediate in tluvse characters between the above-mentioned forms 

 and the continental type, or exhibit a combination of their char- 

 acters, Consequenth\ 1 am obliged to consider the generic name 

 Jllcrocorax, Sharpe, a synonym of Corinm. 



KEY To THE SPECIES AXIJ SUB.SPECIES OK COKVUS. 



a. Feathers of throat elongated, lanceolate, distinctly ontlined. (Ravens.) 

 h. Feathers of neck, npper back, and breast gray l)asally. {Corvus corax.) 

 c. Eighth (third, from outside) primary usually longer than sixth, sometimes 

 longer than seventh. 

 d. Larger, with stouter bill and relatively shorter and thicker tarsi (adult 

 male with exposed culmen averaging 81.5, depth of bill at nostrils 29, 

 tarsus 68). (Northern North America, from Arctic lands to New Bruns- 

 wick, higher Alleghenies, British Columbia, etc.) 



Corvus corax principalis (p. 259) 



dd. Smaller, with more slender bill and relatively longer and thinner tarsi 



(adult male with exposed culmen averaging 74.4, or less, depth of bill 



at nostril 25.6, or less, tarsus more than 68). 



e. Larger, with relatively larger bill (adult male averaging wing 430.8, tail 



236.7, exposed culmen 74.4, depth of bill at nostrils 25.6, tarsus 69.8). 



(Western United States and southward through Mexico .to highlands 



of northern Honduras. ) Corvus corax sinuatus (p. 262) 



ee. Smaller, with relatively smaller bill (adult male averaging wing 402.6, 

 tail 221, exposed culmen 68.2, depth of bill at nostrils 24.2, tarsus 68.4). 

 (Revillagigedo Islands, western Mexico, north to San Clemente and 



Santa Catalina islands, California.) Corvus corax clarionensis (p. 264) 



cc. Eighth primary (third from outside) usually sliorter than sixth, never (?) 

 longer than seventh. (Commander Islands, Kamchatka. ) 



Corvus corax behringianus (extralimital) '^ 

 III). Feathers of neck, upper l)ack, and l)reast pure white ba.«ally. (Southwestern 



United States and Mexican plateau. ) Corvus cryptoleucus (p. 265) 



aa. Feathers of throat normal (short and blended). (Crows. ) 



b. Nostrils completely hidden by antrorse nasal ])himes, the latter directi'<l forward 

 in line with longitudinal axis of maxilla. 



(iCornis corax behringianus Dybowski, Bull. Soc. Zool. France, 1883, 263 (Bering 

 Island, Commander group, Kamchatka). — Corvufi f/rcbnitzkii Stejneger, Proe. Biol. 

 Soc. Wash., ii, 1885 (pub. Apr. 10, 1884), 97 (Bering I.; coll. U. S. Nat. Mus.). 

 The characters of this form are given in view of the possibility that it may oceur as a 

 straggler in some of the westernmost Aleutian Islands. 



10384— VOL 3—03 17 



