18S4.I IIknsiiaw oh II Ncxv GuU Jroin Alaska. 25 I 



an inch; there is a slight trace of thjs qolor on the inner web near the 

 tip. On the fifths the slate begins .25 of an inch from tip, extends .50 of 

 an inch along the web, then makes an acute angle with the shaft for one 

 inch. The slate on the inner web is limited to the margin, where it 

 forms a sipall bar-like spot. The sixth is white at the tip, fading gradu- 

 ally into bluish gray. The tips of the secondaries and tertiaries are 

 pure white for an inch and a half or more from the tip, making a strongly 

 defined wing-band. Bill yellow, with a vermilion spot at the angle of the 

 lower mandible. 



Dimensions. Wing, 17.25; tail, 8.90; culmen, 2^20; bill from nostril, 

 1. 00; bill from gape, 3.00; height at anterior end of nostril. .86; tarsus, 

 3.00; middle toe and claw, 2.90. , , 



Habitat: Alaska (St. Michael's). 



For the sake of comparison I append measurements of L. kiivilietii 

 The first set are as given by Mr. Brewster (Bull. N. O., C, Oct. 

 1S83, p. 217) ; the second are taken by myself from a specimen (<J ad.) 

 collected by Mr. Kumlien in Cumberland Sound; (i) Wing, 16.25; 

 culmen, 1.75; bill from nostril, .85; bill from gape, 2.60; height 

 at anterior end of nostril, .65; tarsus, 2.35; middle toe and ' claw, 

 2.27. — (2) Wing, 16.10; tail, 7.20; culmen, 1.80; bill from anterior end 

 of nostril, .83; bill from gape, 2.66; height at anterior end of nostril, .68. 



It is evident at a glance that this Gull is a close ally of L. 

 Vkumlieiii., which bird indeed it may represent upon the N. W. 

 Pacific coast. The main point of distinction is size, nelsoni 

 being considerably larger. The pattern of primaries is essen- 

 tially the same, though the barred appearance of the primaries, 

 which is conspicuous in the specimen of kninlieni^ referred to 

 above as collected by Kumlien, is not so marked. The slate- 

 gray of the primaries is also very much darker than in kjimlieui. 

 Nelsoni is at once distinguished from glancescens by its lighter 

 .mantle, as well as bv its patterned primaries. Its resemblance to 

 glaucus is much closer, the two being of about the same size, 

 and the color of the mantle is also about the same. In both 

 glaucus and glaucescens the primaries are concolor With the 

 mantle, while in both nelsoni ?ind ku7n/ieni the primaries exhibit 

 a, distinct pattern. The relations of the two last seem, in fact, to 

 be vei'}' similar to \\\osq oi glancits and glattcescetis. and to those 

 said to be borne by lezicopterz/s and glazicopterns. Though 

 bearing a superficial resemblance to glaucescetis^ nelsoni is, per- 

 haps, nearer L. argentatns. the larger i-ace of which it resem- 

 bles in size and in the color of the mantle. From a}gentatns. 

 however, it difters in. having the pattern of the primaries brownish 

 gray instead of black. The colored spaces of the primaries are 



