72 ORNITHOLOGICAL EXPLORATIONS. 



In size it is somewhat intermediate between marinus and argentatus. 

 My specimen comes very close to average measurements of marinus^ 

 while having wings an inch longer than the male specimen from Japan, 

 collected by Captain Blakiston (No. 1085, Hakodadi, March 1, 1878), 

 and determined by Saunders as marinus^ but which I suppose belongs 

 to the present species. The bill is decidely slenderer than in either of 

 these species, while of the same shape. 



The colors of the naked parts are essentially the same, for although 

 the angle of mouth and the eye-ring are rather pale in my specimens, 

 these parts may possibly assume more vivid colors later in the season. 

 The feet are more reddish than in marinus^ being even slightly more so 

 than in argentatus, and without the faintest trace of yellowish. 



As already remarked, the shade of the mantel is rather dark, being 

 only a trifle lighter than that of marinus, or intermediate between occi- 

 dentaUs and dominicanus, and exactly of the same tint as in occidentaUs," 

 only considerably deeper and darker. It consequently needs no com- 

 parison with argentatus or cachinnans, in this respect differing from 

 them nearly as much as they do from marinus. 



Characteristic of the wing pattern is the presence of a well-developed 

 " wedge " on the inner web of the first prim ary as distinctive from marinus, 

 as well as the absence of a similar wedge on the outer webs of the sec- 

 ond to fourth primary, in which it differs from cachinnans and argenta- 

 tus. The mirror on the second primary is also peculiar, resembling, 

 however, the pattern of the corresponding quill in L. cachinnans. In 

 the third primary the large white spot at the end of the gray wedge is 

 very characteristic. It may thus be seen that while the second primary 

 shows less white than in marinus and argentatus, the third has more of 

 the same color than is the case in the latter two species and in cachin- 

 nans. 



On the UOtb of April, 1883, 1 observed for the first time, among nu- 

 merous L. glaucescens on the reef at Staraja Gavan, eastern shore of Ber- 

 ing Island, a few gulls of about the same size, but with the tips of the 

 wings black, and the mantle dark, almost blackish. Four days later I 

 met a couple of birds on the western shore, near the village, and on 

 May 2 an<l 5, I observed them at the same i^lace, the latter date some 

 twelve to twenty individuals, partly in company with glaucescens, partly 

 by themselves. The same day the specimen described above was ob- 

 tained. They were not seen on the island since, and were in fact, un- 

 known to tlie natives, so that it is sale to say that this species only 

 visits the Commander Island occasionally, inasmuch as a "Tschaika" 



