258 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



c. Bill less compressed, higher terminally, where more abruptly decurved. 

 d. Larger (wing 264.5 or more); plumage moderately lustrous, essentially 

 black. 

 e. Larger (wing averaging more than 279.5, exposed culmen averaging 47 or 

 more, tarsus averaging 51 or more) ; under parts faintly glossed with 

 violet. {Corvus americanus. ) 

 /. Larger (exposed culmen of adult male averaging more than 51, tarsus 

 averaging more than 60.5). 

 g. Larger, with relatively smaller bill and feet; wing of adult male aver- 

 aging 321, tail 181, exposed culmen 51.5, tarsus 61.5. (Eastern 

 North America, except Florida and extreme northern districts.) 



Corvus americanus americanus (p. 267) 

 gg. Smaller, with relatively larger bill and feet; wing of adult male 

 averaging 304, tail 174, exposed culmen 51.8, tarsus 62.5. (Penin- 

 sula of Florida. ) Corvus americanus pascuns (p. 269) 



ff. Smaller (exposed culmen of adult male averaging less than 48, tarsus 

 averaging less than 58). 

 g. Larger, with relatively larger feet; wing of adult male averaging 302.5, 

 tail 170.5, exposed culmen 48, tarsus 57.5, middle toe 36. (Western 



United States. ) Corvus americanus hesperis (p. 270) 



gg. Smaller, with relatively smaller feet; wing of adult male averaging 

 283.^, tail 137.5, exposed culmen 46.5, tarsus 51, middle toe 33. 

 (Northwest coast, from Puget Sound to Kadiak Island and Alaska 



peninsula.) Corvus americanus caurinus (p. 272) 



ee. Smaller (wing averaging less than 279.5, exposed culmen averaging less 

 than 45.5, tarsus averaging less than 48); under parts rather distinctly 

 glossed with green or greenish blue. (Atlantic and Gulf coasts of 

 United States, from Massachusetts to Texas. ) 



Corvus ossifragus (p. 273) 

 dd. Smaller (wing less than 260); plumage highly lustrous, dark steel blue, 

 with violet on pileum, wings, etc. (Mexico. ) 



Corvus mexicanus (p. 275) 



cc. Bill more compressed, less deep terminally, where culmen less strongly 



decurved. 



d. Larger (wing 261, tail 149, exposed culmen 51, tarsus 51.5); bill narrower, 



less high at base; nasal plumes reaching far in advance of nostrils. 



(Haiti.) Corvus palmarum (p. 276) 



dd. Smaller (wing 233, tail 134.5, exposed culmen 43.5, tarsus 48.5) ; bill more 

 conical, higher at base; nasal plumes reaching but little in advance of 



nostril. (Cuba.) Corvus minutus (p. 276) 



bb. Nostrils exposed, the nasal plumes directed obliquely upward. 

 c. Smaller (wing less than 254); back and under parts sooty slate. (Jamaica.) 



Corvus jamaioensis (p. 277) 

 cc. Larger (wing 279.5 Of more); back and under parts glossy black. 

 d. Feathers of neck and body gray basally. (Cuba.).. Corvus nasicus (p. 278) 

 dd. Feathers of neck and body pure white basally. ( Conms leacognaphalus. ) 

 e. Larger, with smaller feet (wing averaging more than 305, tarsus averag- 

 ing 53, middle toe averaging 40) ; plumage less glossy. (Porto Eioo. ) 

 Corvus leucognaphalus leuoognaphalus (p. 278) 

 ee. Smaller, with larger feet (wing averaging less than 305, tarsus averaging 

 57, middle toe averaging 44) ; plumage more glossy. (Haiti.) 



Corvus leucognaphalus erythrophthalmus (p. 279) 



