198 D wight, A New Species of Loon. . Upd! 



in proportion, compared to the Northern ones; the gonys, in most cases 

 forms a sharper angle. 



This notice about the Diver I dedicate to P. P. Suschkin. 



It is quite obvious from the foregoing translation that suschkini 

 is merely slightly differentiated from the purple-throated Gavia 

 arcticus and as pacificus is also a like variation, it follows that the 

 green-throated birds are without a name, for the synonyms of 

 arctica refer without exception to European birds. My attention 

 was first directed to the Siberian birds some years ago by Dr. L. 

 B. Bishop when we were examining skins of Loons at the American 

 Museum of Natural History. I propose for them the following 

 name : — 



Gavia viridigularis sp. nov. 



Type. — No. 76665, American Museum of Natural History; adult male; 

 Gichega (or Ghijiga) northeastern Siberia; September 16, 1894; collected 

 by N. G. Buxton. 



Diagnosis. — The green coloration of the throat is the essential character 

 that sets this species apart from arclica and its races, which all have purple 

 throats. 



Description of type. — Top of head smoke gray, paler and drab-tinged 

 on nape, sides of head darker and purplish, rest of upper surface a slightly 

 lustrous greenish-black, the scapulars with twelve to fourteen broad (6-7 

 min.) white bars of quadrate spots, the sides of the hind neck with ten or 

 twelve similar though narrower bars and the outer surface of the wings 

 with small semi-ovate white spots. The throat is a velvety dusky olive- 

 green if held towards the light and an olivaceous black with slight purplish 

 tints if held away from it; the upper part of the throat and the chin are a 

 darker green much like the back. The throat is bordered by narrow white 

 stripes enclosing broader stripes of black and it is crossed at its upper part 

 by about ten short white longitudinal stripes; numerous narrow black and 

 white streaks radiate from its lower border along the sides of the jugulum. 

 The wing quills, the tail, the under tail coverts, the tibiae, and an obscure 

 line across the anal region are dusky. The lining of the wing is white. The 

 bill in dried skins is a dull grayish-black, and the feet are black. Measure- 

 ments (in millimeters) — wing 322, tail 59, tarsus 90, toe with claw 115, 

 culmen 69, depth of bill 17. 



The sexes are alike in plumage but the female is slightly smaller. Average 

 of two males, wing 321, tail 59.5, tarsus 88, toe with claw 108.5, culmen 68, 

 depth of bill 18: — average of five females, wing 316, tail 58.2, tarsus 82.6, 

 toe with claw 101.6, culmen 64, depth of bill 17. 



Range. — Northeastern Siberia and extreme western Alaska. 



