Bangs and Penard — Six New American Birds. 91 



North America, but larger; under parts averaging darker, i. e., more dusky 

 and less white. 

 Measurements. — 

 AT. b. majorinus. — Type, adult cf : wing, 115.0; tail, 76.0; tarsus, 15.0; 

 exposed culmen, 18.5. 



Eighteen males: wing, 111.3 (107.0-116.5); tail, 72.8 (70.0-77.0); 

 tarsus, 14.9 (14.5-15.0); exposed culmen, 18.6 (18.0-20.0). 



Twenty females: wing, 104.8 (100.5-109.0); tail, 68.9 (66.0-74.0); 

 tarsus, 14.4 (13.5-15.0); exposed culmen, 17.4 (16.5-18.5). 

 N. b. borealis.— Nineteen males: wing, 105.6 (103.0-109.0); tail, 67.5 

 (64.0-70.0); tarsus, 14.2 (13.5-15.0); exposed culmen, 17.0 (16.0- 

 18.0). 



Nine females: wing, 99.4 (96.0-102.5); tail, 64.3 (61.0-67.0); 

 tarsus, 13.9 (13.5-14.5); exposed culmen, 16.6 (16.0-17.5). 

 Specimens examined. — 



N. b. majorinus, forty-four; — Montana, 1; Oregon, 3; Colorado, 11; 

 California, 16; Arizona, 11; Mexico: Chihuahua, 1 9 (migrant — 

 wing 110, perhaps a male) ; Colombia : La Concepcion, 1 9 (migrant — 

 wing, 111.0, probably a male). 

 N. b. borealis, forty-five: — Maine, 14; New Hampshire, 4; Massachu- 

 setts, 7; Michigan, 2; New York, 2; North Carolina, 1 cf (migrant); 

 Texas: Lomita Ranch, 1 d' (migrant); Mexico: Tamaulipas, 8 <f cf, 

 2 9 9 (migrant); Costa Rica, 3 cTcf (migrant); Panama: Boquite. 

 1 <? (migrant). 

 In coloration the new form is practically identical with true borealis 

 except that the underparts have a little less white. This character is far 

 from constant, but in our series is noticeable. In size, however, the two 

 forms are sufficiently distinct to enable us to trace their migration routes, 

 provided the sexing is reliable. 



The Peruvian specimens recorded by Taczanowski (Orn. Perou, II, 1884, 

 p. 317 — wing, 113; tail, 74) and by Hellmayr (Archiv fur Naturgesch., 85 

 Jahrg., 1920, Abt. A, Heft 10, p. 60— adult 9, wing, 103; tail, 74) belong 

 without doubt to the western form. 



Melanotis caerulescens effuticius, subsp. nov. 



Type.—M. C. Z., 220,386, adult d"; Mexico: Chihuahua, Hacienda de 

 San Rafael, 4 May, 1888; M. Abbott Frazar. 



Subspedfic characters. — Similar to Melanotis caerulescens caerulescens 

 (Swainson) of eastern Mexico, and of about the same size, but averaging 

 paler bluish, less grayish blue, throughout; pileum, superciliary region, 

 throat, and chest, paler, brighter bluish. 



Measurements.— Type, adult cf: wing, 115.0; tail, 125.0; tarsus, 30.0; 

 exposed culmen, 22.5. 

 Specimens examined. — 



M. c. effuticius, twenty-two: — Northwestern Mexico: Alamos (Sonora), 

 4; Chihuahua, 14; Los Flores (Sinaloa), 1; Escuinapa (Sinaloa), 

 1; Santiago (Tepic), 2. 



